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Calculator directory

Calculator Library

Free online calculators for everyday math, money, dates, shopping, school, health, work, and quick text checks. Each page keeps the inputs, result, formula, and assumptions visible.

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All calculatorsMoney calculators
Popular calculators49 calculators
Percentage CalculatorUse this percentage calculator for common percent math: find a percent of a number, calculate percentage change, or work out what percent one value is of another.Mortgage CalculatorUse this mortgage calculator to estimate a monthly house payment from home price, down payment, interest rate, taxes, insurance, and HOA fees.Budget CalculatorUse this budget calculator to compare monthly income against housing, food, transportation, debt, savings, and other spending.Emergency Fund CalculatorUse this emergency fund calculator to estimate how much cash to keep for emergencies and how long it may take to reach the target.Tax Estimate CalculatorUse this tax estimate calculator for a quick planning estimate from annual income, deductions, an estimated tax rate, credits, and tax already withheld.BMI CalculatorUse this BMI calculator to estimate body mass index, BMI category, and a healthy BMI weight range from height and weight.Discount CalculatorUse this discount calculator to find the sale price, savings, and estimated total after tax for coupons, markdowns, and shopping deals.Average CalculatorUse this average calculator to find the mean, median, count, and sum from numbers separated by commas, spaces, or line breaks.Profit Margin CalculatorUse this profit margin calculator to compare revenue, cost of goods, operating expenses, markup, break-even revenue, and target net margin.Net Worth CalculatorUse this net worth calculator to add assets, subtract liabilities, and track a simple personal balance sheet.
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Browse by category

Find the calculator that matches the question.

Categories stay broad, but each calculator page is named around the exact task people search for.

Quick daily mathEveryday Calculators

Common calculators for percentages, dates, tips, age, time, units, and other everyday questions.

Personal financeMoney Calculators

Simple calculators for budget, tax estimates, emergency funds, debt payoff, loans, savings, rent, salary, and household money math.

Body and nutritionHealth Calculators

Quick health and fitness calculators for BMI, calorie estimates, weight ranges, and everyday wellness planning.

Work and pricingBusiness Calculators

Practical calculators for rates, invoices, cash runway, profit, pricing, and small business planning.

Social metricsSocial Media Calculators

Useful calculators for engagement rate, views, sponsorship pricing, and social media revenue estimates.

Words and namesText and Writing Tools

Small text utilities for word count, characters, usernames, bios, headlines, domains, and social posts.

Popular calculator tasks

Start from the decision you are trying to make.

These groups connect common everyday questions to the calculators that answer them directly.

Shop, split, and compare prices

Fast calculators for discounts, sales tax, tips, unit prices, and percentage checks before you buy.

Discount calculatorSale price, savings, and estimated taxUnit price calculatorCompare price per ounce, pound, item, or servingSales tax calculatorPre-tax price, tax amount, and totalTip calculatorTip amount and split bill total

Plan monthly money decisions

Budget, paycheck, emergency fund, rent, and savings calculators for household planning.

Budget calculatorMonthly income, spending, savings, and surplusPaycheck calculatorGross pay, estimated deductions, and take-home payEmergency fund calculatorSavings target and time to reach itRent affordability calculatorRent budget from income and monthly obligations

Compare loans and payoff plans

Loan calculators for monthly payments, mortgage planning, refinancing, auto loans, and debt payoff.

Mortgage payment calculatorPrincipal, interest, taxes, insurance, and HOALoan comparison calculatorCompare monthly payment, total interest, and total costCredit card payoff calculatorPayoff time and interest by payment amountRefinance calculatorPayment change, breakeven, and lifetime interest

Check dates, time, and school math

Everyday calculators for date ranges, age, time duration, grades, GPA, averages, and fractions.

Days between dates calculatorCalendar days, weeks, and optional end-date countingTime duration calculatorElapsed time between two clock timesGPA calculatorCredits, grades, quality points, and GPAAverage calculatorMean, median, count, and sum

Estimate health and nutrition numbers

Simple health calculators for BMI, calorie targets, macros, and due-date estimates.

BMI calculatorBody mass index, category, and weight rangeCalorie calculatorMaintenance calories and goal estimatesMacro calculatorProtein, carbs, and fat targetsDue date calculatorEstimated pregnancy due date and milestones

Price, bill, and run a small business

Practical calculators for pricing, invoicing, margins, freelance rates, and cash runway.

Profit margin calculatorGross margin, net margin, markup, and break-even revenueFreelance rate calculatorHourly rate, day rate, billable hours, and revenue targetInvoice generatorLine items, tax, discount, subtotal, and balance dueCash runway calculatorRunway from cash balance, revenue, and monthly expenses

Work with text and online metrics

Writing and social calculators for word counts, sponsorship pricing, engagement, and online publishing checks.

Word counterWords, characters, sentences, and reading timeBrand deal calculatorSponsorship pricing from audience and deliverablesTikTok engagement rate calculatorEngagement rate from views, likes, comments, and sharesPercentage calculatorQuick percent math for reports, posts, and dashboards

Newly added

Recent calculator pages.

New pages are kept live-only here so the directory feels like a working reference with finished calculators.

Profit Margin CalculatorFreelance Rate CalculatorInvoice GeneratorTax Estimate CalculatorEmergency Fund CalculatorDebt Snowball CalculatorNet Worth CalculatorRetirement CalculatorRefinance CalculatorLoan Comparison CalculatorSavings Interest CalculatorAverage CalculatorUnit Price CalculatorPaycheck CalculatorGPA Calculator

Calculator standards

Built for checking the math, not reading around it.

Tool pages prioritize the calculator, the formula, a worked example, benchmarks, limitations, and related calculators.

No account required
Formula shown
Examples included
Mobile friendly