Free Online Calculators

Simple, fast calculators for everyday math, health, finance, and conversions. No sign-up, no app — everything runs in your browser.

Basic Calculator

Add, subtract, multiply, divide. Standard four-function calculator with keyboard support.

Scientific Calculator

Trig functions, logarithms, powers, factorials, and constants. Deg/Rad toggle.

Percentage Calculator

What is X% of Y? What % is X of Y? Percentage change and more.

Calculate exact age in years, months, days, weeks, and total days from a birthdate.

Body Mass Index from height and weight. Metric and imperial units.

Calculate tip and split the bill. Quick presets for 10%, 15%, 18%, 20%, 25%.

Length, weight, temperature, volume, area, speed, time, and data conversions.

Date Calculator

Days between dates, add/subtract days, and find the day of the week for any date.

Loan Calculator

Monthly payment, total interest, and total cost for any loan amount and term.

Discount Calculator

Sale price after % off, what % off, or the original price from sale + discount.

Investment Calculator

Compound growth projections for S&P 500, NASDAQ, MSCI World, and more — with an interactive chart.

About these calculators

Calculator Prodigy provides free, browser-based calculators for common everyday calculations. All computation happens locally — no data is sent to any server. The tools work on desktop and mobile without any sign-up.

Common uses

Quick math without reaching for a physical calculator
Checking discounts and sale prices while shopping
Splitting restaurant bills and calculating tips
Finance: estimating monthly loan payments
Health: BMI and age calculations
Work: unit conversions, date math, percentage changes