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Home & Trade

Paint, concrete, electrical, and property calculators.

Wire Size Calculator: Pick a wire gauge from load amps, run length, voltage, and a maximum voltage-drop percentOctober 1, 2026 · 4 min read · Use the free Wire Size Calculator to pick a wire gauge from load amps, run length, voltage, and a maximum voltage-drop percent.Voltage Drop Calculator: Calculate voltage drop and percent drop for copper or aluminum wire by AWG, amps, distance, and phaseOctober 1, 2026 · 4 min read · Use the free Voltage Drop Calculator to calculate voltage drop and percent drop for copper or aluminum wire by AWG, amps, distance, and phase.Vehicle Depreciation Calculator: Project car value year by year with a declining-balance depreciation rateOctober 1, 2026 · 3 min read · Use the free Vehicle Depreciation Calculator to project car value year by year with a declining-balance depreciation rate.Tithing Calculator: Calculate a tithe or any percent of weekly, monthly, or yearly incomeOctober 1, 2026 · 3 min read · Use the free Tithing Calculator to calculate a tithe or any percent of weekly, monthly, or yearly income.Spray Foam Calculator: Convert wall area and foam thickness into board feet, spray foam kits, and material costOctober 1, 2026 · 4 min read · Use the free Spray Foam Calculator to convert wall area and foam thickness into board feet, spray foam kits, and material cost.Seller Net Calculator: Estimate seller net proceeds after commission, mortgage payoff, closing costs, and repairsOctober 1, 2026 · 3 min read · Use the free Seller Net Calculator to estimate seller net proceeds after commission, mortgage payoff, closing costs, and repairs.Retirement Calculator: Project retirement savings from a current balance, monthly contribution, return, and yearsOctober 1, 2026 · 3 min read · Use the free Retirement Calculator to project retirement savings from a current balance, monthly contribution, return, and years.Rental Property Calculator: Estimate cap rate, monthly cash flow, cash-on-cash return, and mortgage payment for a rental propertyOctober 1, 2026 · 4 min read · Use the free Rental Property Calculator to estimate cap rate, monthly cash flow, cash-on-cash return, and mortgage payment for a rental property.Refinance Calculator: Compare your current mortgage payment with a refinance, including break-even months and total interestOctober 1, 2026 · 3 min read · Use the free Refinance Calculator to compare your current mortgage payment with a refinance, including break-even months and total interest.Plant Spacing Calculator: Count how many plants fit in a garden bed with square or triangular spacingOctober 1, 2026 · 4 min read · Use the free Plant Spacing Calculator to count how many plants fit in a garden bed with square or triangular spacing.Ohm's Law Calculator: Solve voltage, current, resistance, and watts with Ohm's law from any two electrical valuesOctober 1, 2026 · 4 min read · Use the free Ohm's Law Calculator to solve voltage, current, resistance, and watts with Ohm's law from any two electrical values.Molarity Calculator: Calculate solution molarity from grams and molar mass, or the grams to weigh for a target molarityOctober 1, 2026 · 4 min read · Use the free Molarity Calculator to calculate solution molarity from grams and molar mass, or the grams to weigh for a target molarity.Miter Angle Calculator: Find the miter saw angle and interior corner for a square, hexagon, octagon, or any equal-sided frameOctober 1, 2026 · 4 min read · Use the free Miter Angle Calculator to find the miter saw angle and interior corner for a square, hexagon, octagon, or any equal-sided frame.Marketplace Fee Calculator: Calculate seller fees, shipping, product cost, net profit, and margin for an online marketplace listingOctober 1, 2026 · 4 min read · Use the free Marketplace Fee Calculator to calculate seller fees, shipping, product cost, net profit, and margin for an online marketplace listing.Lumber Calculator: Calculate board feet, linear feet, and lumber cost from thickness, width, length, and board countOctober 1, 2026 · 3 min read · Use the free Lumber Calculator to calculate board feet, linear feet, and lumber cost from thickness, width, length, and board count.Loan Comparison Calculator: Compare two loans side by side on monthly payment, total interest, and total amount paidOctober 1, 2026 · 4 min read · Use the free Loan Comparison Calculator to compare two loans side by side on monthly payment, total interest, and total amount paid.kW to kVA Calculator: Convert kilowatts to kVA with power factor, and estimate single-phase or three-phase ampsOctober 1, 2026 · 4 min read · Use the free kW to kVA Calculator to convert kilowatts to kVA with power factor, and estimate single-phase or three-phase amps.Kerf Calculator: See how many pieces a board yields after saw kerf, and how many boards to buyOctober 1, 2026 · 4 min read · Use the free Kerf Calculator to see how many pieces a board yields after saw kerf, and how many boards to buy.Hull Speed Calculator: Calculate displacement hull speed in knots, mph, and km/h from waterline lengthOctober 1, 2026 · 3 min read · Use the free Hull Speed Calculator to calculate displacement hull speed in knots, mph, and km/h from waterline length.Hexagon Quilt Calculator: Estimate fabric area for hexagon quilt pieces from side length, seam allowance, and how many hexes you needOctober 1, 2026 · 4 min read · Use the free Hexagon Quilt Calculator to estimate fabric area for hexagon quilt pieces from side length, seam allowance, and how many hexes you need.Fuel Mix Calculator: Calculate 2-stroke oil for a 50:1, 40:1, 32:1, or 25:1 gas mix in ounces and millilitersOctober 1, 2026 · 4 min read · Use the free Fuel Mix Calculator to calculate 2-stroke oil for a 50:1, 40:1, 32:1, or 25:1 gas mix in ounces and milliliters.EV Charging Cost Calculator: Calculate electric vehicle charging cost, kWh, and hours from miles, efficiency, and charger kWOctober 1, 2026 · 4 min read · Use the free EV Charging Cost Calculator to calculate electric vehicle charging cost, kWh, and hours from miles, efficiency, and charger kW.Employee Cost Calculator: Estimate fully loaded employee cost from salary, benefits percent, and employer payroll taxOctober 1, 2026 · 4 min read · Use the free Employee Cost Calculator to estimate fully loaded employee cost from salary, benefits percent, and employer payroll tax.Electricity Cost Calculator: Estimate appliance electricity cost from watts, hours per day, and your price per kWhOctober 1, 2026 · 4 min read · Use the free Electricity Cost Calculator to estimate appliance electricity cost from watts, hours per day, and your price per kWh.Down Payment Calculator: Compare 3%, 5%, 10%, 20%, and a custom down payment, with loan amount and whether PMI is likelyOctober 1, 2026 · 4 min read · Use the free Down Payment Calculator to compare 3%, 5%, 10%, 20%, and a custom down payment, with loan amount and whether PMI is likely.Deck Calculator: Estimate deck boards, joists, and square footage from deck size, board width, gap, and joist spacingOctober 1, 2026 · 4 min read · Use the free Deck Calculator to estimate deck boards, joists, and square footage from deck size, board width, gap, and joist spacing.Compost Calculator: Balance browns and greens by volume and see how much to add for a target compost ratioOctober 1, 2026 · 4 min read · Use the free Compost Calculator to balance browns and greens by volume and see how much to add for a target compost ratio.Coffee Ratio Calculator: Calculate pour-over, French press, drip, cold brew, and espresso water from a coffee dose and brew ratioOctober 1, 2026 · 4 min read · Use the free Coffee Ratio Calculator to calculate pour-over, French press, drip, cold brew, and espresso water from a coffee dose and brew ratio.Closing Cost Calculator: Estimate buyer closing costs from lender fees, title, inspection, appraisal, and prepaid tax and insuranceOctober 1, 2026 · 4 min read · Use the free Closing Cost Calculator to estimate buyer closing costs from lender fees, title, inspection, appraisal, and prepaid tax and insurance.CFM Calculator: Calculate airflow CFM from room volume and air changes per hour for a fan, hood, or workshopOctober 1, 2026 · 4 min read · Use the free CFM Calculator to calculate airflow CFM from room volume and air changes per hour for a fan, hood, or workshop.Cat Age Calculator: Convert cat years and months into an approximate human-equivalent ageOctober 1, 2026 · 3 min read · Use the free Cat Age Calculator to convert cat years and months into an approximate human-equivalent age.How Car Trade-In Equity Is CalculatedOctober 1, 2026 · 4 min read · Trade-in equity is the offer minus the loan payoff. See a worked example, what the tax line assumes, and when to use the free calculator.Business Valuation Calculator: Estimate a small-business value from seller earnings and revenue using multiples you chooseOctober 1, 2026 · 4 min read · Use the free Business Valuation Calculator to estimate a small-business value from seller earnings and revenue using multiples you choose.Budget Calculator: Split monthly income across housing, food, transport, and debt, then see what is left and the savings rateOctober 1, 2026 · 4 min read · Use the free Budget Calculator to split monthly income across housing, food, transport, and debt, then see what is left and the savings rate.BTU Calculator: Estimate room cooling BTU from size, ceiling height, sun, people, windows, and a kitchen load, plus AC tonsOctober 1, 2026 · 4 min read · Use the free BTU Calculator to estimate room cooling BTU from size, ceiling height, sun, people, windows, and a kitchen load, plus AC tons.Aquarium Calculator: Convert tank dimensions to gallons and liters, plus heater watts, water-change volume, and salt doseOctober 1, 2026 · 3 min read · Use the free Aquarium Calculator to convert tank dimensions to gallons and liters, plus heater watts, water-change volume, and salt dose.Air Changes Calculator: Find air changes per hour from room cubic feet and fan CFM, plus minutes for one full air changeOctober 1, 2026 · 4 min read · Use the free Air Changes Calculator to find air changes per hour from room cubic feet and fan CFM, plus minutes for one full air change.AC Tonnage Calculator: Convert home square footage, insulation, and climate into cooling tons and BTU, rounded to the next half tonOctober 1, 2026 · 4 min read · Use the free AC Tonnage Calculator to convert home square footage, insulation, and climate into cooling tons and BTU, rounded to the next half ton.Absorption Rate Calculator: Calculate real estate absorption rate and months of housing supply from sales and active listingsOctober 1, 2026 · 4 min read · Use the free Absorption Rate Calculator to calculate real estate absorption rate and months of housing supply from sales and active listings.3D Print Cost Calculator: Estimate 3D print cost from filament grams, spool price, print hours, printer watts, and electricity rateOctober 1, 2026 · 4 min read · Use the free 3D Print Cost Calculator to estimate 3D print cost from filament grams, spool price, print hours, printer watts, and electricity rate.

How to use 542+ tools on this site

Each tool is a separate page. The title is the task, the sentence under the title is the scope, and the form is the product. Type the text, choose the file, or enter the numbers you already have. The result stays on that page. You can change one field and compare a second case without starting over.

480 tools run in the browser. The file or the figures stay on your device, which is why those pages are marked private. They work without an account. AI writers and handwriting OCR send the input to a server so a model can run, and the page says so. The free plan includes a small daily limit for those server tools. Pro removes the limit. Do not paste passwords or account numbers into a server tool.

Search from the header when you know the tool name. Open a category when you only know the kind of job. Calculator pages are estimates: a payment, a yard of concrete, or a calorie figure is only as good as the rate, the unit, and the date you typed. PDF and image pages follow the file you upload. If the page never mentions a rule that applies to your bank, school, clinic, or city, treat the output as a draft and check the source that actually governs the decision.

Read the notes under the form before you rely on a number. They repeat the scope, the steps, and the questions people ask. Related tools sit at the bottom when the next step is a different calculation or a different file. The categories below are the whole library.

AI-Powered Tools. AI assistants for developers and job seekers — explain code, generate SQL, write cover letters and interview answers, check résumés for ATS, debug errors, commits, PRs, docs and tests. AI assistants for developers & job seekers. Open that category and read the line under each tool name before you click. The line is the job the tool actually does.

Handwriting OCR. AI-powered handwriting tools — OCR in 30+ languages, form & table extractors, math to LaTeX, Markdown conversion, and note summarizers. Upload a photo and get editable digital text. OCR, forms, tables, math & notes. Open that category and read the line under each tool name before you click. The line is the job the tool actually does.

Freelancer Tools. Free client-side tools for freelancers — contracts, proposals, NDAs, rate calculators, quotes, and change orders. No signup, no subscription. Contracts, rates & client docs — free. Open that category and read the line under each tool name before you click. The line is the job the tool actually does.

DevOps Tools. Client-side generators and validators for infrastructure, CI/CD and networking — configs, manifests and scripts you can copy straight into your project. Configs, manifests & scripts. Open that category and read the line under each tool name before you click. The line is the job the tool actually does.

Health & Fitness. Free health and fitness calculators — hydration, macros, heart-rate zones, training and more. Instant, private and running entirely in your browser. Fitness, nutrition & wellbeing. Open that category and read the line under each tool name before you click. The line is the job the tool actually does.

Text Tools. Browser-based utilities for counting, converting, cleaning, and transforming text. Write, clean & transform text. Open that category and read the line under each tool name before you click. The line is the job the tool actually does.

Developer Tools. Client-side coding utilities for formatting, converting, encoding and inspecting data. Format, convert & debug code. Open that category and read the line under each tool name before you click. The line is the job the tool actually does.

Security & Password Tools. Privacy-first, in-browser tools for passwords, hashing, encryption and key generation. Passwords, hashing & crypto. Open that category and read the line under each tool name before you click. The line is the job the tool actually does.

PDF Tools. Browser-based tools to merge, split, convert, compress, and edit PDF files. Merge, split & convert PDFs. Open that category and read the line under each tool name before you click. The line is the job the tool actually does.

Image Tools. Browser-based tools to convert, resize, compress, crop, and edit images. Resize, compress & convert images. Open that category and read the line under each tool name before you click. The line is the job the tool actually does.

Color Tools. Browser-based color pickers, converters, palette and gradient generators. Pick, convert & build palettes. Open that category and read the line under each tool name before you click. The line is the job the tool actually does.

Calculators. Financial, health, math, date and everyday calculators that run entirely in the browser. Finance, health & math. Open that category and read the line under each tool name before you click. The line is the job the tool actually does.

Unit Converters. Instant client-side converters for length, weight, volume, temperature, and other measurement units. Convert any unit instantly. Open that category and read the line under each tool name before you click. The line is the job the tool actually does.

SEO & Web Tools. Comprehensive SEO suite — keyword research, technical audits, content optimization, rank tracking, backlinks, internal linking, schema, and AI SEO workflows. Research, audits, schema & AI SEO. Open that category and read the line under each tool name before you click. The line is the job the tool actually does.

Social Media Tools. Client-side helpers for crafting, styling, and mocking up social media content and posts. Captions, fonts & mockups. Open that category and read the line under each tool name before you click. The line is the job the tool actually does.

Content Creator Tools. Free browser tools for YouTubers, podcasters & social creators — video editing, script extraction, voiceovers, captions & more. No signup for browser tools; AI script studio uses daily free runs. Video editor, script studio & voiceovers. Open that category and read the line under each tool name before you click. The line is the job the tool actually does.

Converters & Generators. Client-side data converters and utility generators for developers, students, and everyday users. Data converters & generators. Open that category and read the line under each tool name before you click. The line is the job the tool actually does.

Home & Trade Calculators. Free home, workshop, electrical, and property calculators — BTU, AC tonnage, lumber, deck, voltage drop, refinance, rental cash flow, and more. Runs in your browser. Home, workshop, electrical & property. Open that category and read the line under each tool name before you click. The line is the job the tool actually does.

Pick the tool whose description matches the input you have. If the description does not mention that input, it is the wrong page. Run the form, read the result next to the labels, and only then copy it into a document, a message, or a spreadsheet.

How to read a result

A calculator answers the question printed on the page. A mortgage page returns principal, interest, tax, and insurance when you enter those amounts. It does not know your lender’s fees, your credit score, or a rate that changes next month. Change the rate, the term, or the down payment and read the new payment next to the old one before you decide. The same habit works for a loan, a retirement contribution, a paint job, or a calorie target: one input at a time, then the line that moved.

Units are part of the answer. A length converter shows both sides of the pair you picked. A concrete page asks for feet or metres because a yard of concrete is a volume, not a length. If the label says per month, do not type a yearly figure in that box. Dates matter on age, pregnancy, countdown, and interest pages: the day you enter is the day the formula uses. Round only after you have the full figure, and keep the same rounding when you compare two cases.

File tools follow the file. A PDF merge keeps page order as you arranged the files. Split and extract keep the pages you selected. Compress makes the file smaller and can soften images inside it. Rotate, crop, watermark, and page numbers change the pages you see, not the words in a scanned image unless the page says it runs OCR. An image resizer changes pixels. A format converter changes the container. Download the result and open it before you send it. If the preview looks wrong, the source file is still on your device and you can run the tool again.

Text tools work on the text in the box. A counter reports words, characters, and sentences for that box only. Case, find-and-replace, and duplicate-line tools rewrite that box. They do not open a document on your computer until you paste. JSON, CSV, and code formatters expect valid input; an error line means the text is not in the shape the tool described. Fix the text or pick the converter that matches the format you actually have.

Search opens a list of every tool name and its one-line description. Type the job, not a slogan: mortgage, merge pdf, word counter, bmi. The match is the name and the description, so a short specific phrase finds the page faster than a long sentence. Category menus are the same library grouped by the kind of work. A tool that is not built yet is marked soon and does not pretend to calculate.

The guide under each tool is the place to check limits. It names the inputs, what the formula leaves out, and the questions people ask before they use the number. Related links are the next tool when the job continues, such as a payment after a loan amount, or a JPG after a PDF page. The blog explains one job in a longer article and links to the tool that does the work. Use the article when you want the reasoning, and the tool when you already have the figures.

Browser tools need a current browser and JavaScript. A very large PDF or image can be slow because it is processed on your machine. Server tools need a connection and count toward the free daily limit. Create an account only if you want that limit lifted. The result on a private page is not stored by the site. Copy what you need, then close the tab if the file was sensitive.