Calculators
Free online calculators for everyday numbers. Work out percentages, BMI, loan payments, compound interest, tips, and discounts, with results that update as you type. Everything runs in your browser, so nothing you enter is sent anywhere.
All calculators
401(k) Calculator
Project your 401(k) balance at retirement from your contributions, employer match, and expected return, year by year.
Amortization Schedule Calculator
Build a full payment-by-payment schedule for any fixed-rate loan, with the payoff date and the interest you save by paying extra.
APY Calculator
Turn a nominal rate and compounding frequency into the true annual percentage yield, project a balance, or reverse solve the rate.
Area Calculator
Pick a shape, enter its dimensions, and get the area and perimeter at once.
Auto Loan Calculator
Estimate the monthly payment, total interest, and total cost of a car loan from the price, down payment, trade-in, sales tax, and rate.
Average Calculator
Paste a list of numbers and get the mean, median, mode, range, and standard deviation instantly, updated as you type.
Blood Alcohol Content Calculator
Estimate your blood alcohol content from your sex, body weight, how much you drank, and how long ago you started. An estimate, never a measurement.
BMI Calculator
Work out body mass index from height and weight, in metric or imperial, with the WHO adult category and a healthy weight range for your height.
BMR Calculator
Estimate your basal metabolic rate from sex, age, height, and weight, comparing the Mifflin-St Jeor and Harris-Benedict equations, with an optional daily calorie estimate.
Body Fat Calculator
Estimate your body fat percentage from tape measurements using the U.S. Navy method, then see your fat mass and lean mass. Metric or imperial, updated as you type.
Break-Even Calculator
Enter your fixed costs, price per unit, and variable cost to see the break-even units, break-even revenue, and contribution margin, updating as you type.
BTU Calculator
Estimate the cooling capacity a room needs in BTU per hour from its size, ceiling height, sun exposure, insulation, and use, then read the matching tonnage and a suggested air conditioner size.
CAGR Calculator
Work out the compound annual growth rate from a beginning value, an ending value, and the number of years, with total growth shown alongside.
Calories Burned Calculator
Estimate the calories you burn from any activity using its MET value, your body weight, and how long you moved.
Circle Calculator
Enter any one of radius, diameter, circumference, or area and get the other three at once.
Coffee to Water Ratio Calculator
Turn a brew ratio into an exact recipe. Enter a ratio and one amount to get the coffee, water, cups, and tablespoons of grounds.
Compound Interest Calculator
Project how a balance grows with compound interest and monthly contributions, year by year.
Concrete Calculator
Work out how much concrete a slab, footing, column, or round pour needs, with the volume in cubic yards or cubic meters and how many 40, 60, or 80 lb bags to buy.
Credit Card Payoff Calculator
See how long a credit card balance takes to clear, what it costs in interest, and the payment needed to hit a target date.
Debt Snowball Calculator
List your debts, add whatever extra you can pay each month, and get your debt-free date, total interest, and the exact order your balances clear.
Debt-to-Income Ratio Calculator
See your debt-to-income ratio the way a lender does, with the front-end housing ratio and a rating band, updated as you type.
Discount Calculator
Work out the sale price, total savings, and overall percent off for stacked percentage or fixed-amount discounts, or reverse it to find the discount between two prices.
Distance Between Two Points Calculator
Enter two points in 2D or 3D and get the straight-line distance, the midpoint, and the change on each axis at once.
Dog Age Calculator
Convert your dog's age into human-equivalent years by breed size, and see whether they count as a puppy, adult, or senior.
Down Payment Calculator
Enter a home price and a percent or cash amount to see the down payment, loan amount, and loan-to-value ratio.
Due Date Calculator
Estimate a pregnancy due date from the last period and cycle length, with the current week, trimester, and milestone dates.
Electricity Cost Calculator
Work out what any device costs to run from its wattage, the hours it runs, and your price per kWh.
Exponent Calculator
Raise any base to a power and get the result, its expanded form, scientific notation, and roots, updated as you type.
Factorial Calculator
Enter a non-negative whole number and get its factorial computed exactly, with the digit count, scientific notation, and trailing zeros, updated as you type.
Fraction Calculator
Add, subtract, multiply, or divide two fractions and read the result as a simplified fraction, a decimal, and a mixed number, live as you type.
Fuel Cost Calculator
Enter a trip distance, your fuel efficiency in mpg or L/100km, and the price of fuel to get the total cost, the fuel you need, and the cost per mile or kilometre.
Future Value Calculator
Project what a present value plus regular contributions grows to, with adjustable compounding and contribution timing.
Gas Mileage Calculator
Enter the distance you drove and the fuel you used, or two odometer readings, and get your fuel economy as MPG, L/100km, and km/L, plus the cost per mile or kilometre when you add a fuel price.
GCD and LCM Calculator
Enter two or more whole numbers to find their greatest common divisor and least common multiple, with the prime factorization of each, updated as you type.
Golden Ratio Calculator
Split any length by the golden ratio. Enter the whole, the longer part, or the shorter part, and get the other two plus the ratio.
GPA Calculator
Turn letter grades and credit hours into a weighted grade point average on the 4.0 scale, with total credits and quality points, updating as you type.
Heart Rate Zone Calculator
Turn your age or maximum heart rate into five training zones in beats per minute, using percentage of max or the Karvonen heart rate reserve method.
Hourly to Salary Calculator
Turn an hourly wage into annual, monthly, biweekly, weekly, and daily pay, updated as you type.
Home Affordability Calculator
See how much house you can afford. Enter your income, monthly debts, and down payment to get the maximum home price, loan amount, and monthly payment your budget supports.
Ideal Weight Calculator
Estimate ideal body weight from height and sex with four classic formulas, and see the healthy weight range for your height.
Inflation Calculator
See how inflation erodes the value of money over time, or what a past amount is worth today.
Loan Calculator
Work out the monthly payment, total interest, and full amortization schedule for any fixed-rate loan.
Loan Payoff Calculator
See how many months until a balance is paid off, and how much interest and time an extra monthly payment saves.
Logarithm Calculator
Enter a number and any base to find log base b of x, with the natural log, log base 10, and log base 2 shown alongside, plus an antilog mode for the inverse.
Macro Calculator
Turn a daily calorie target into carb, protein, and fat grams with balanced, low-carb, high-protein, keto, or fully custom splits.
Markup Calculator
Turn a cost and markup into a selling price, or a cost and price into the markup, with profit and margin worked out both ways.
Mortgage Calculator
Work out your monthly mortgage payment, with property tax and home insurance folded in, plus the total interest and total cost over the life of the loan.
Mulch Calculator
Work out how much mulch a garden bed needs from its length and width or a total area and the depth you want, in cubic yards, cubic feet, and bags, with an optional cost.
Net Worth Calculator
Add up what you own and what you owe to see your net worth, with a category-by-category percentage breakdown, updated as you type.
One Rep Max Calculator
Estimate your one-rep max from a weight and rep count using three standard strength formulas, with a table of training weights for 1 to 10 reps.
Overtime Pay Calculator
Add up regular, overtime, and double-time hours into total pay and your effective hourly rate, updated as you type.
Ovulation Calculator
Estimate your ovulation date, fertile window, next period, and due date from the first day of your last period, cycle length, and luteal phase.
Paint Calculator
Work out how much wall paint a room needs from its size or wall area, the number of coats, and the coverage on your paint can, with doors and windows deducted.
Paycheck Take-Home Calculator
Estimate the net pay that lands in your account after federal income tax, Social Security, Medicare, and a flat state rate.
Percentage Calculator
Find X% of a number, what percent one number is of another, and the percentage change between two values, live as you type.
Percentage Change Calculator
Enter an old value and a new value to see the percent change, whether it is an increase or a decrease, the absolute difference, and the multiplier, live as you type.
Percentile Calculator
Paste a list of numbers to get any percentile, the quartiles Q1, Q2, and Q3, and the percentile rank of a single value.
Permutation and Combination Calculator
Enter n and r to get the number of permutations and combinations, plus the factorials behind them.
Probability Calculator
Enter the chance of two independent events and get the probability that both, either, or neither happen, plus a probability to odds converter.
Profit Margin Calculator
Enter your cost and selling price to see gross profit, profit margin, and markup at once, updating as you type.
Protein Intake Calculator
Estimate how much protein to eat each day from your body weight and goal, with a recommended range and a per-meal split.
Pythagorean Theorem Calculator
Enter any two sides of a right triangle to solve for the third, plus the area, perimeter, and both acute angles.
Quadratic Formula Calculator
Enter the coefficients a, b, and c to solve ax² + bx + c = 0, with real or complex roots, the discriminant, the nature of the roots, and the parabola vertex.
Ratio Calculator
Reduce a ratio to lowest terms, or solve a proportion for the one value you are missing.
Recipe Scaler Calculator
Enter the servings a recipe makes and the servings you want, and every ingredient is recalculated for you. Mixed fractions like 1 1/2 are read correctly and results round to friendly amounts.
Refinance Calculator
Compare your current mortgage against a new rate and term to see the new monthly payment, how much you save each month, when the closing costs pay for themselves, and the effect on total interest.
Retirement Calculator
Project your savings balance at retirement, split into what you put in and what growth adds.
ROI Calculator
Work out return on investment, net gain, and annualized return from what you put in and what it is worth.
Roof Pitch Calculator
Convert between roof pitch, angle, slope factor, and grade from a single entry.
Running Pace Calculator
Enter any two of distance, time, and pace to solve for the third, in kilometres or miles, with predicted finish times for 5K, 10K, half, and full marathon.
Salary to Hourly Calculator
Convert a yearly salary into an hourly rate, and see the matching daily, weekly, biweekly, and monthly pay. Adjust your hours, days, and weeks and every figure updates instantly.
Sales Tax Calculator
Add sales tax to a net amount, or remove it from a tax-inclusive total. Enter the amount and rate and the tax and total update as you type.
Sample Size Calculator
Enter a confidence level, margin of error, and expected proportion to get the sample size your survey needs, with and without a finite population correction.
Savings Goal Calculator
Find how long it takes to reach a savings target, or the monthly amount you need to hit it by a deadline.
Scientific Calculator
Type a full expression with trigonometry, logarithms, powers, roots, and factorials, and see the result update live as you go.
Simple Interest Calculator
Work out simple interest and the final amount from a principal, an annual rate, and a length of time in years or months.
Sleep Cycle Calculator
Find the best times to go to bed or wake up, timed to complete 90-minute sleep cycles so you rise between cycles instead of mid-cycle.
Slope Calculator
Enter two points to get the slope, the incline angle, the y-intercept, the line equation, and the distance between them.
Square Footage Calculator
Add up the area of rooms and spaces in any shape, mix feet, inches, yards, meters, and centimeters in one list, and get the total in square feet and square meters with an optional material cost.
Square Root Calculator
Enter a number to get its square root, cube root, an optional nth root, and its square, plus whether it is a perfect square.
Standard Deviation Calculator
Paste a list of numbers to get the standard deviation, variance, mean, count, and sum, with the method shown.
Student Loan Calculator
Find the monthly payment, total interest, and payoff date on a student loan, and see how much paying extra each month saves.
TDEE Calculator
Estimate your total daily energy expenditure from age, sex, height, weight, and activity level, then read calorie targets for cutting or bulking.
Tile Calculator
Work out how many floor or wall tiles you need from the room area, the tile size, the grout gap, and a waste allowance, then see how many boxes that is to buy.
Tip Calculator
Work out the tip, the total, and each person's share from any bill, with preset or custom percentages, optional tax, and a round-up.
Triangle Calculator
Enter two legs of a right triangle for the hypotenuse, area, perimeter, and angles, or a base and height for the area.
Unit Price Calculator
Compare two or more products by their price per unit, see which is the better deal, and find out how much you save. Updated as you type.
VAT Calculator
Add VAT to a net price, or remove it from a gross price. Enter the amount and rate and the net, VAT, and gross update as you type.
Volume Calculator
Pick a shape, enter its dimensions, and get the volume, surface area, and conversions to liters and gallons at once.
Water Intake Calculator
Estimate how much water to drink each day from your body weight, daily exercise, and climate, with the total in liters, US ounces, and 8-oz cups.
Weighted Average Calculator
Enter values and their weights to get the weighted mean, with the total weight and the plain average shown for comparison. Updates as you type.
Z-Score Calculator
Enter a value, mean, and standard deviation to get its z-score, percentile, cumulative probability, and two-tailed p-value.
Frequently asked questions
- Are these calculators free to use?
- Yes. Every calculator is free, with no signup, no ads walls, and no usage limits. Open one and start typing.
- Is the data I enter stored or shared?
- No. Calculations run entirely in your browser. Amounts, dates, and measurements never leave your device, which matters when the numbers are salaries, loans, or health details.
- How accurate are the results?
- The math follows the standard formulas for each calculation, and results update instantly as you change any input. For decisions with real financial or medical stakes, treat the results as a starting point and confirm with a professional.
- Do the calculators work on my phone?
- Yes. Every calculator works in any modern browser on desktop and mobile, and stays usable offline once the page has loaded.