All free KindCalc calculators

27 U.S. tools that run in your browser. Pick a calculator, get a number, read the formula on the same page.

Money

Plan a U.S. paycheck, a card payoff, a refinance break-even, a house you can actually bid on, a car note, or a sales-tax total without an account. These tools run locally and show the formula on the same page.

Money

Salary to Hourly Calculator

Convert annual salary to an hourly rate, or hourly pay to yearly salary. Adjust hours per week and unpaid time off.

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Money

Free Paycheck Calculator (2026)

Free U.S. paycheck calculator with 2026 federal tax, FICA, and state income tax. Estimate monthly and biweekly take-home for all 50 states.

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Money

Overtime Calculator

Free U.S. overtime calculator for time-and-a-half or double time. Enter hourly rate and hours this week. FLSA-style weekly overtime after 40 hours.

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Money

401(k) Calculator (2026 Limits)

Free 2026 401(k) calculator: employee deferral, employer match, IRS limits, catch-up, and a projected balance. Private, in your browser.

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Money

Loan Payment Calculator

Calculate a monthly loan payment from amount, rate, and term. See total interest for personal loans and other amortizing debt. For the schedule, use the amortization calculator.

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Money

Amortization Calculator

Build a U.S. loan amortization schedule from amount, rate, and term. See interest vs principal each month, add extra principal, and download CSV.

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Money

Credit Card Payoff Calculator

See how long to pay off a U.S. credit card at your payment versus an estimated minimum. Compare months, interest, and the cost of paying only the minimum.

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Money

Free Mortgage Payment Calculator

Estimate a U.S. monthly mortgage payment with principal, interest, taxes, insurance, HOA, and PMI. Compare 15-year and 30-year terms.

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Money

Mortgage Payoff Calculator

See how extra monthly principal shortens a U.S. mortgage and how much interest you avoid. Compare scheduled P&I with the accelerated payoff.

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Money

Mortgage Refinance Calculator

Compare your current U.S. mortgage with a refinance: new payment, cash break-even, closing costs, and whether a longer term erases the rate cut.

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Money

House Affordability Calculator

Estimate how much house you can afford from U.S. income, debts, down payment, and a 28/36-style DTI cap. See max price and monthly PITI.

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Money

Car Payment Calculator

Estimate a U.S. monthly car payment with price, down payment, trade-in, sales tax, rate, and term. See amount financed and total interest.

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Money

Compound Interest Calculator

See how a balance and monthly contributions grow with compound interest. Annual, quarterly, monthly, or daily compounding. Private, in your browser.

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Money

Inflation Calculator

See what a U.S. dollar amount from one year is worth in another using CPI-U. Convert 1913–2026 prices and show the percent change.

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Money

Tip Calculator

Calculate a U.S. restaurant tip and split the bill. Set percent, tax, and headcount—15%, 18%, 20%, or 25% presets.

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Money

Percentage Calculator

Find X percent of Y, what percent X is of Y, and percent increase or decrease. Instant percent math in your browser.

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Money

Sales Tax Calculator

Add U.S. sales tax to a price by state. Uses 2026 state rates plus average local tax. See the tax amount and the total you’ll pay.

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Everyday

Health screening numbers, dates, U.S. customary and metric units, meeting times, and a 4.0 GPA. Fast answers with the method written out.

Everyday

BMI Calculator

Calculate body mass index from height and weight in metric or imperial units. See the WHO category and the BMI formula.

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Everyday

Age Calculator

Calculate age from a birth date, or the exact difference between two dates in years, months, and days. Leap years included.

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Everyday

Unit Converter

Convert length, weight, and temperature between metric and U.S. customary units. cm to inches, kg to lbs, Celsius to Fahrenheit.

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Everyday

Time Zone Converter

Convert a date and time between world time zones, including U.S. zones and daylight saving. Schedule meetings without the offset guess.

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Everyday

GPA Calculator

Calculate a weighted GPA on a 4.0 U.S. scale. Add courses, letter grades, and credit hours to see your average.

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Utilities

Count words, change case, generate a password, check WCAG contrast, or make a QR code. All of it stays on your device.

Utilities

Word Counter

Count words, characters, sentences, and paragraphs. See reading time as you type or paste. Text never leaves your browser.

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Utilities

Case Converter

Convert text to uppercase, lowercase, title case, sentence case, camelCase, or snake_case. Instant and private.

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Utilities

Password Generator

Generate a random password in your browser with cryptographically strong randomness. Choose length and character sets. Nothing is uploaded.

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Utilities

Color Contrast Checker

Check WCAG contrast between foreground and background colors. See AA and AAA pass/fail for normal and large text.

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Utilities

QR Code Generator

Create a QR code from a URL or text in your browser. Download a PNG. The content is never sent to a server.

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Paycheck by state

High-search U.S. states with 2026 federal, FICA, and state wage tax already selected.

Sales tax pages for the same states: California, Texas, Florida, New York, and every state.