Search our collection of 50+ free online calculators for finance, health, math, and everyday calculations. Fast, accurate, and no sign-up required.
Start with our top 3 most-used free calculators
Browse our collection of free online calculators organized by category
Calculate percentage of a number
Add or subtract percentage from a number
Calculate percentage of a percentage
Calculate percent increase or decrease
Advanced math with trig and logarithms
Add, subtract, multiply, divide fractions
Calculate mean, median, mode and statistics
Generate random numbers or pick items
Calculate factorial (n!) of any number
Find Least Common Multiple with steps
Square root, cube root, and nth root
Calculate powers with step-by-step solutions
Find prime factors with division method
Check if a number is prime
Find Highest Common Factor with steps
Convert between Roman and Arabic numerals
Calculate area, perimeter, volume for 2D & 3D shapes
Calculate right triangle sides using a² + b² = c²
Calculate nPr and nCr with step-by-step solutions
Generate Fibonacci numbers with golden ratio
Calculate compound interest with contributions
Calculate simple interest on principal
Compare simple and compound interest
Calculate sale prices and savings
Compound annual growth rate
Calculate loan payments and amortization
Project your investment growth over time
Plan how much to save for your goals
Calculate purchasing power over time
Plan your retirement savings
Calculate debt payoff time and cost
Add or remove GST/VAT from prices
Calculate profit margins and markups
Track and calculate subscription costs
Calculate tips and split bills
Compare renting versus buying a home
Calculate SIP returns with step-up and inflation
Calculate lumpsum returns with inflation adjustment
Calculate monthly auto loan payments
Calculate trip fuel costs and gas mileage
Estimate power costs by appliance usage
Calculate seed, mulch, fertilizer needs
Scale recipe ingredients up or down
Find your perfect ring size
Convert US, UK, EU shoe sizes
Most questions map to one specific tool. A few common ones and where to start:
Weighing a 48-month against a 60-month term? Put both into the Car Payment Calculator and compare the total interest paid, not just the monthly payment. A lower monthly figure over a longer term almost always costs more overall.
Investing a lump sum once, use the Lumpsum Calculator. Adding a fixed amount every month instead, use the SIP Calculator. For a plain interest projection, the Compound Interest Calculator shows how the same money grows at different compounding frequencies.
Start with the BMI Calculator for a quick weight-to-height ratio, then use the Calorie Calculator to estimate daily energy needs and the Body Fat Calculator for a composition estimate BMI alone cannot give.
Finance: the difference between simple and compound interest is easy to see with a real number. Put $10,000 at 5% for 10 years: simple interest adds a flat $500 a year for a $15,000 total, while annual compounding earns interest on interest and reaches about $16,289. Our finance tools make that comparison, plus loan amortization, retirement projections, and tax figures like GST and VAT.
Health: BMI measures weight relative to height, TDEE (total daily energy expenditure) estimates the calories you burn in a day, and body-fat percentage estimates composition. They answer different questions, so the health section keeps them separate rather than reducing everything to one number.
Math: the math tools show their working, not just a final answer. The percentage, fraction, prime factorization, and geometry calculators lay out each step so they double as a way to check homework or understand a method.