All calculators

Calculate your monthly mortgage payment, total interest, and full amortization. Free, accurate, and works in any currency.

Estimate the maximum home price you can afford based on your income, debts, down payment, and interest rate. Uses the standard 28/36 rule.

See if refinancing your mortgage saves money. Calculates new payment, monthly savings, total interest savings, and break-even time.

Calculate monthly payment, total interest, and total cost for any fixed-rate loan. Works for personal, auto, student, and small-business loans.

Calculate monthly car payment, total interest, and total cost. Supports trade-in, sales tax, and down payment.

See how money grows over time with compounding. Enter principal, rate, time, and optional monthly contributions to project future value.

Calculate simple interest on a loan or deposit. Returns interest amount, total, and effective rate.

Calculate what an amount of money in one year is worth in today's dollars, using a configurable inflation rate.

Convert between APR (annual percentage rate) and APY (annual percentage yield). Critical for comparing loans and savings accounts.

Compare debt payoff strategies: snowball (smallest balance first) versus avalanche (highest rate first). See total interest and payoff timeline.

See how long it takes to pay off a credit card balance and how much interest you'll pay. Compare minimum payments versus a fixed monthly amount.

Estimate your retirement number using the 4 % rule, and project whether your current savings + monthly contributions will get you there.

Calculate the right size for your emergency fund based on monthly expenses, family situation, and job security.

Calculate return on investment as a percentage and annualized return. Compare investments fairly by adjusting for the holding period.

Compare the long-run cost of renting versus buying a home over a chosen number of years. Includes mortgage interest, property tax, maintenance, and investment opportunity cost.

Calculate how long it'll take to save for a down payment on a home, factoring in your current savings, monthly contribution, and investment return.

Calculate how long until you reach a savings target, or how much to save monthly to hit it by a target date.

Project college savings growth with tuition inflation. Models 529 plans and shows monthly contribution needed to fund a 4-year degree.

Estimate US federal income tax owed for 2026 using the official IRS brackets. Marginal vs effective rate shown.

Convert between hourly, weekly, biweekly, monthly, and annual pay. Handles full-time, part-time, and freelance hours per week.

Estimate your real take-home hourly rate after taxes. Useful for comparing freelance rates against W-2 salary positions.

Calculate tip amount, total bill, and per-person share split across any number of people. Works for any currency and tip percentage.

Calculate sales tax, VAT, or GST on any purchase. Works two ways: add tax to a price, or back out the pre-tax price from a total.

Calculate sale price after percentage discount, or work out the original price from a sale price. Handles stacked discounts too.

Convert between major world currencies using live exchange rates from the European Central Bank, updated daily.

Calculate cryptocurrency profit, loss, and ROI from entry price, exit price, position size, and trading fees.

Estimate years to payback for a residential solar PV system based on system cost, annual production, electricity rate, and rate inflation.

Compare cost of living between cities using purchasing-power-parity (PPP) factors. See what salary you'd need to maintain your standard of living.

Estimate wedding costs by guest count and style, with category breakdown (venue, catering, photography, attire, flowers).

Estimate annual childcare cost by care type and city tier. Compares daycare, nanny, au pair, and family-shared arrangements.

Calculate commission earnings on flat-rate, tiered, and revenue-share structures. Useful for sales reps and managers planning quotas.

Calculate your Body Mass Index (BMI) instantly. Free BMI calculator for adults in metric and imperial units, with WHO category breakdown.

Calculate your basal metabolic rate (BMR) and total daily energy expenditure (TDEE) — the calories you burn at rest and with activity.

Calculate daily protein, carbohydrate, and fat targets for cutting, maintaining, or bulking. Supports keto, low-carb, and balanced diets.

Estimate body fat percentage from neck, waist, and hip measurements using the US Navy circumference formula.

Compute ideal body weight using four classic formulas (Devine, Robinson, Miller, Hamwi) plus a healthy-BMI range.

Estimate lean body mass (LBM) using the Boer, James, and Hume formulas. Used for medication dosing and body composition tracking.

Calculate waist-to-hip ratio (WHR), a body shape metric linked to cardiovascular health risk.

Estimate how much water to drink per day based on your weight, activity level, and climate. Returns liters, ounces, and glasses.

Calculate your five training heart rate zones from age and resting heart rate using the Karvonen heart-rate-reserve formula.

Convert between pace, time, and distance. Predict marathon, half-marathon, 10K, and 5K finish times from a shorter race result.

Estimate your one-rep max from a recent set using six common formulas (Epley, Brzycki, Lombardi, Mayhew, O'Conner, Wathen).

Calculate the calorie deficit needed to lose weight by a target date, and project how long realistic deficits will take.

Estimate your pregnancy due date and how many weeks pregnant you are. Supports last menstrual period (LMP), conception date, and ultrasound dates.

Estimate ovulation date and fertile window from your last period and cycle length. Useful for trying to conceive or natural cycle tracking.

Calculate your eating and fasting windows for 16:8, 18:6, 20:4, OMAD, and custom intermittent fasting protocols.

See how much caffeine remains in your body hours after drinking it, and when it's safe to sleep without disruption.

Estimate blood alcohol content based on drinks, body weight, sex, and time. Includes sober-time estimate.

Calculate optimal bedtime or wake-up time based on 90-minute sleep cycles, with 15-minute fall-asleep buffer.

Track accumulated sleep debt over a week and see how many extra hours you'd need to recover.

Estimate your annual carbon footprint in tonnes of CO2 from home energy, driving, flights, and diet.

Convert your dog's age to human years using the modern AVMA-aligned formula — not the outdated 7× myth.

Convert your cat's age to human years using the modern veterinary aging chart, with milestones for kitten, adult, senior, and geriatric stages.

Calculate daily, monthly, and yearly pet food cost based on bag size, price, and daily portion.

Track pickleball scores for singles and doubles. Follows official USAPA rules including server number and side-out logic.

Convert mouse sensitivity between FPS games (Valorant, CS2, Apex, Overwatch). Calculate eDPI and equivalent in-game sensitivity.

Calculate exact age in years, months, days, hours, and minutes from any birthdate. Also shows total days lived and next birthday countdown.

Calculate exact days, weeks, months, and years between any two dates. Optionally exclude weekends to get business days.

Count business days (Mon-Fri) between two dates, or add a number of business days to a start date.

Calculate total hours worked given clock-in and clock-out times, with optional unpaid break deduction.

Convert any time between two time zones with automatic daylight-saving handling. Built for distributed teams and travel planning.

Live countdown to any future date — days, hours, minutes, and seconds. Great for birthdays, holidays, vacations, and project deadlines.

Add or subtract time durations in hours, minutes, and seconds. Useful for video editing, project tracking, and time math.

Find the ISO 8601 week number and day of year for any date. Critical for European business, project planning, and SQL date queries.

Add or subtract any number of days, weeks, months, or years to a starting date. Returns the resulting date.

Calculate percentage of a number, percentage change between two numbers, and what percent X is of Y. Fast, clean, and works with any values.

Convert between metric and imperial units for length, mass, volume, and temperature. Fast, accurate, and works with any value.

Add, subtract, multiply, and divide fractions. Shows simplified result and decimal equivalent. Handles mixed numbers.

Compute mean, median, mode, range, variance, and standard deviation from a list of numbers.

Simplify ratios, scale them to a target value, and convert ratios to decimals, percentages, and parts.

Online scientific calculator with trigonometric, logarithmic, exponential, and power functions. Works with degrees or radians.

Solve ax² + bx + c = 0 using the quadratic formula. Shows both real and complex roots.

Calculate width or height for a target aspect ratio (16:9, 4:3, 1:1, 21:9). Useful for video, design, and screen sizing.

Calculate tank volume in gallons and liters from dimensions. Handles rectangular, bowfront, cylinder, and hexagon shapes.

Calculate the GCD (greatest common divisor) and LCM (least common multiple) of any list of integers using Euclid's algorithm.

Convert numbers to Roman numerals and back. Supports 1 through 3,999,999 using standard and vinculum notation.

Convert between binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16). Essential for programming, networking, and computer science.

Convert colors between HEX, RGB, and HSL formats. Includes a live color preview for designers and developers.

Convert between bytes, KB, MB, GB, TB, and PB using both binary (1024) and decimal (1000) conventions.

Convert internet speeds between Mbps and MB/s, plus calculate how long a file takes to download at any speed.

Calculate subnet mask, network address, broadcast, usable hosts, and IP range from any CIDR notation.

Calculate the area of a room or surface in square feet or square meters. Supports rectangle, triangle, and circle shapes.

Calculate how much paint you need for a room. Accounts for wall area, coats, doors, windows, and typical 350 sq ft/gallon coverage.

Calculate how many tiles you need for a floor or wall, including a waste allowance for cuts and breakage.

Estimate the BTU rating needed to cool or heat a room based on size, insulation, climate, and sun exposure.

Calculate concrete volume for slabs, footings, columns, and pads in cubic yards and cubic meters, with bag-mix equivalents.

Calculate board feet for any quantity of lumber. Useful for hardwood pricing, framing estimates, and project cost-out.

Calculate cubic yards and bags of mulch, soil, or gravel needed for a garden bed at your chosen depth.

Calculate how many drywall sheets you need for walls and ceilings, including waste and screw count.

Convert between roof pitch (rise/run), angle in degrees, and slope percentage. Useful for roofing, siding, and accessibility.

Calculate the number of stairs, individual rise, run, and stringer length for any total height.

Calculate how many bags of fertilizer you need for a lawn at the recommended nitrogen rate (typically 1 lb N per 1,000 sq ft).

Calculate carpet area needed in square yards, including waste, plus padding and total installed cost.

Calculate the number of fence posts, panels, and bags of concrete needed for a fence run, plus total material cost.

Calculate fuel economy in MPG (miles per gallon) or L/100km from distance driven and fuel used. Converts between both standards.

Estimate the fuel cost of a trip based on distance, your vehicle's mileage, and current fuel price.

Calculate the cost and time to charge an electric vehicle from any state of charge to any target, at any kW charger speed and electricity rate.

Project your car's resale value year by year using typical depreciation curves for new and used vehicles.

Calculate monthly lease payment from MSRP, negotiated price, residual value, money factor, and lease term.

Compare two tire sizes — diameter, circumference, revolutions per mile, and speedometer correction percentage.

Scale any recipe up or down by changing the serving count. Multiplies every ingredient quantity proportionally.

Convert recipe measurements between cups, grams, milliliters, ounces, tablespoons, and teaspoons.

Convert oven temperatures between Fahrenheit, Celsius, gas marks, and descriptive levels (slow, moderate, hot).

Calculate coffee grounds and water for any brew strength and yield. Supports pour-over, French press, AeroPress, and drip ratios.

Calculate calories per serving by adding ingredient calories and dividing by the number of servings the recipe makes.

Calculate baker's percentages for bread dough — hydration, salt, yeast, and starter percentages relative to flour weight.

Convert oven recipes to air fryer settings — reduce temperature by 25°F and time by 20-25 %.

Calculate your grade point average on the standard US 4.0 scale. Supports any number of courses, credit hours, and letter or numeric grades.

Calculate the grade you need on your final exam to achieve your target grade in the course.

Estimate how long it will take to read a piece of text or a given word count, at various reading speeds.

Test your typing speed in words per minute (WPM) and accuracy with a built-in 60-second typing test.

Count words, characters (with and without spaces), sentences, paragraphs, and reading time of any text.

Convert between word count and page count for any font, size, and spacing setup. Useful for essay sizing and manuscript pacing.

Plan your day using the Pomodoro technique. Calculate how many work sessions fit in a time block, with breaks and long-break intervals.

Plan a trip budget: flights, accommodation, food, transport, activities, and a buffer. Returns per-person and group totals.

Estimate flight duration from distance, average ground speed, and headwind. Useful for trip planning and connection timing.

Estimate how many days of jet-lag recovery to expect based on time zones crossed and direction of travel.

Calculate full road trip cost: fuel, lodging, food, and incidentals — split per person and per day.

Calculate per diem total for business travel based on city rate, days, and partial-day allowances.

Check if your bag is within airline limits and estimate overweight/oversize fees for major carriers.