Free Online Math Calculators
29 free tools — Percentage, BMI, GPA, tip, age, and compound interest
Percentage Calculator
Calculate percentages, find what percent one number is of another, or add/subtract percentages. Simple and fast.
Tip Calculator
Calculate tips and split bills easily. Enter your bill amount, tip percentage, and number of people to split between.
BMI Calculator
Calculate your Body Mass Index from height and weight. Understand your BMI category and health implications.
Age Calculator
Calculate exact age in years, months, days, hours, and minutes. Find how old you or anyone is from a birth date.
GPA Calculator
Calculate your Grade Point Average from letter grades and credit hours. Supports 4.0 scale and weighted GPAs.
Average Calculator
Calculate mean, median, and mode of a set of numbers. Find arithmetic average instantly.
Random Number Generator
Generate random numbers within a range. Pick integers or decimals. Perfect for games, sampling, and simulations.
Compound Interest
Calculate compound interest on investments or savings. See how your money grows over time with different rates and periods.
Percentage Change
Calculate the percentage increase or decrease between two values. Perfect for tracking growth, sales, or price changes.
Percentage Off
Calculate sale prices when a percentage discount is applied. Find the final price after any percent off.
Standard Deviation
Calculate standard deviation and variance for a set of numbers. Sample and population modes supported.
Scientific Calculator
Full-featured scientific calculator with trig, log, exponents, and more. Use it free in your browser.
Binary Calculator
Perform binary arithmetic: add, subtract, multiply, and divide binary numbers. See results in binary, decimal, and hex.
Hex Calculator
Perform hexadecimal arithmetic and convert between hex, decimal, and binary. Essential for programming and web colors.
Roman Numeral Converter
Convert numbers to Roman numerals and Roman numerals to numbers. Handles values from 1 to 3999.
Prime Number Checker
Check if a number is prime. See nearest primes (next and previous) and prime factorization for small numbers.
Fraction Calculator
Add, subtract, multiply, and divide fractions. Simplify fractions and convert between fractions and decimals.
Matrix Calculator
Compute determinant, transpose, and multiplication for 2×2 and 3×3 matrices. Useful for linear algebra coursework.
Quadratic Formula Solver
Solve quadratic equations using the quadratic formula. Find real and complex roots for ax² + bx + c = 0.
Pythagorean Theorem
Calculate the missing side of a right triangle using a² + b² = c². Solve for hypotenuse or either leg.
Area Calculator
Calculate the area of common shapes: rectangle, triangle, circle, trapezoid, ellipse, and regular polygons.
Volume Calculator
Calculate the volume of 3D shapes: cube, rectangular box, sphere, cylinder, cone, and pyramid.
Discount Calculator
Calculate discounts on multiple items. See line totals, grand total, and how much you save in a single view.
Margin Calculator
Calculate profit margin from revenue and cost. Cross-converts to markup so you can compare both views.
Markup Calculator
Calculate markup percentage from cost and selling price. Set prices based on a target markup for your products.
Conversion Rate Calculator
Calculate conversion rate from visitors and conversions, or reverse-solve for the conversions needed at a target rate.
ROI Calculator
Calculate Return on Investment with optional annualized ROI for holding periods longer than a year.
CAGR Calculator
Calculate Compound Annual Growth Rate. Measure consistent annual growth over multiple years.
CPM Calculator
Calculate Cost Per Mille (thousand impressions). Bidirectional: solve for CPM, spend, or impressions.
About Math & Calculators
Math calculators here cover the calculations most people actually run: percentage of a number, percentage change, BMI in metric or imperial, GPA from a list of grades, tip split by party size, age between two dates, simple average, and compound interest with optional monthly contributions. Every result is shown alongside the formula or the breakdown so the answer is checkable.
BMI uses the WHO category bands (underweight, normal, overweight, obese) and shows where your value sits on the scale. The compound interest calculator lets you set rate, term, compounding frequency, and recurring deposits, and shows year-by-year growth. The GPA calculator supports both 4.0 unweighted and weighted scales with letter-grade input.
These are general-purpose calculators. For tax, medical, or investment decisions that have real consequences, verify the numbers with a qualified professional. Everything runs in your browser — your inputs never leave your device.