Calculators
Math, finance and health calculators.
Calculators do the math for you and show the result the moment you type. Work out percentages, discounts and tips, run everyday finance numbers, or compute health figures like BMI and ideal targets. They are made for shoppers checking a sale price, students and professionals crunching numbers, and anyone who would rather get an instant, accurate answer than reach for a phone calculator. Each tool explains the formula behind the result, so you can trust how the number was reached. Everything is computed locally in your browser — nothing you enter is sent anywhere — and there is no account to create. Free, instant, and designed to give you the answer at a glance.
31 tools
All tools → Age Calculator Enter a birth date and choose the date to calculate against to get exact age in years, months and days — plus total days, weeks, hours, and the next birthday after that date. BMI Calculator Enter your height and weight to instantly get your BMI plus the standard WHO weight category, in metric or imperial units. BMR Calculator Find your basal metabolic rate (resting calorie burn) from three formulas at once, instantly and privately. Body Fat Calculator Estimate your body fat percentage from tape measurements using the U.S. Navy method, with a practical likely range — instantly and privately. Business Days Calculator Count the working days between two dates — or add N business days to a date — with configurable weekends and your own holidays, instantly in your browser. Calorie Calculator Enter your sex, age, height, weight, and activity level to instantly see your daily maintenance calories plus target calories for weight loss and muscle gain. Car Payment Calculator Estimate your monthly car payment and total cost from vehicle price, down payment, trade-in, payoff, fees, sales tax, term, and APR. Compound Interest Calculator Enter a starting amount, optional regular contributions, an interest rate, and a time horizon to instantly get your future value, total contributions, total interest earned, and a year-by-year growth breakdown. Date Difference Calculator Pick a start and end date to see the gap as years, months and days plus total days, weeks and hours — with an include-end-day toggle and a business-days-only count. Days Until Date Calculator Pick any date and instantly see the days until (or days ago), plus weeks, weekdays only, months, and a live countdown. Discount Calculator Enter an original price and a discount percentage to instantly see the final sale price and exactly how much money you save. Due Date Calculator Estimate your pregnancy due date, gestational week, and trimester from your last period, conception date, or IVF transfer — instantly and privately in your browser. Fraction Calculator Add, subtract, multiply, or divide two fractions and instantly get the answer in lowest terms, as a mixed number, and as a decimal, with the steps shown. GPA Calculator Add your courses, pick a letter grade and credit hours for each, and instantly see your weighted GPA, total credits, and an optional new cumulative GPA on the standard US 4.0 scale. Grade Calculator Add up your weighted assignment and exam scores to get your current class percentage, and find out exactly what you need on the final to hit your target grade. Hours Calculator Add up your worked hours from clock-in and clock-out times — including multiple shifts, breaks, overnight spans, and optional pay. Ideal Weight Calculator See your ideal body weight from four classic formulas at once, side by side, plus a BMI-based healthy range. IRR Calculator Solve a single-cash-flow IRR (fill any three of investment, exit value, multiple, years or rate and get the fourth) and, in the same page, layer on a hurdle rate (simple or compound) and a full GP carry waterfall with optional catch-up to see exactly how the profit splits between LPs and the GP. Loan Calculator Enter loan amount, interest rate, and term to instantly see your monthly payment, total interest, total repaid, and a full month-by-month amortization schedule. Macro Calculator Turns your stats and goal into daily calories plus exact protein, carb, and fat grams. Mortgage Calculator Enter home price, down payment, term, and rate to instantly see your full monthly PITI payment, total interest, total cost, and amortization breakdown. Pace Calculator Solve for running pace, time, or distance from the other two — with speed in km/h and mph, race presets, and both km and miles. Percentage Calculator Solve any percentage question in one place — what is X% of Y, what percent X is of Y, and the percent change from one number to another — with results that update live as you type. Retirement Calculator See how your savings compound to retirement, whether you hit your target, and how many years the pot can fund — all in one screen. Sales Tax Calculator Add sales tax to a price or reverse it out of a tax-inclusive total to find the pre-tax price and tax portion, instantly. Savings Calculator Find out how long it takes to hit a savings goal — or how much to save each month to hit it by a deadline — with compound interest. Sleep Calculator Pick a wake-up time to see the best bedtimes, or go to bed now to see the best alarm times — built around 90-minute sleep cycles and the time it takes to fall asleep. Square Footage Calculator Measure rooms of any shape, add them into one total, convert sq ft to sq m, and estimate material cost — instantly and privately. TDEE Calculator Find your maintenance calories plus fat-loss and muscle-gain targets from age, sex, height, weight, and activity level. Tip Calculator Enter a bill and tip percentage to instantly see the tip amount, the grand total, and exactly how much each person owes when splitting the check. Week Number Find what week it is today, the ISO 8601 week of any date with its Monday–Sunday range, or convert a year + week back into dates.