Free Online Calculators

Just enter the loan amount, annual interest rate and term to instantly calculate your monthly payment, total repayment and total interest. Supports equal-payment and equal-principal methods, with a modern chart of the principal-vs-interest breakdown.

Work out how much you need to save each month to reach a goal, based on the target amount, saving period and annual return. If you have current savings, their future value is subtracted to find the required amount.

Calculate the future value and interest of a compound investment from your principal, annual rate, and term. Supports annual, semi-annual, quarterly, and monthly compounding, and shows the effective annual rate.

Calculate simple interest and the total (principal plus interest) from a principal, annual rate, and term. Set the term in years plus extra days, and see the interest earned per year.

Compare simple and compound interest totals for the same principal, rate, and term. See the difference and year-by-year growth in a table and bar chart.

Enter a nominal annual rate and how often interest compounds (annually, semiannually, quarterly, monthly, or daily) to instantly get the effective annual rate (EAR). See how it differs from the nominal rate and the annual interest gap on a given principal.

Estimate your basal metabolic rate (BMR) — the energy your body needs at rest — from your sex, age, height, and weight using the Harris-Benedict equation.

Estimate your total daily energy expenditure (TDEE) from your sex, age, height, weight, and activity level. Also shows target calories for cutting, maintaining, and bulking.

Enter your height and weight to instantly calculate your BMI, ideal weight (BMI 22), and weight category based on WHO/JASSO standards.

Enter your height to see the weight for each BMI from 16 to 35 in a table and conversion chart. Ideal, beauty, and model weights are shown together.

Just enter your height to instantly calculate your ideal weight (BMI 22). It also shows your beauty weight (BMI 20), underweight threshold (BMI 18.5), and overweight threshold (BMI 25).

Just enter your height to calculate ideal, beauty, Cinderella and model weight at once by BMI standard. Enter your current weight to also see the gap to each goal.

Just enter a value and pick a unit to instantly convert between meters, centimeters, inches, feet, shaku, nautical miles, light-years and more. A single table shows the value in every other unit at once.

Convert between m², acres, hectares, square feet, and Japanese units like tsubo and jo. Enter a value, pick a unit, and see every conversion at once.

Enter a value and pick a unit to convert at once between mL, L, m³, cubic inches, cubic feet, US/UK gallons, pints and quarts, plus the Japanese go, sho, to and koku.

Convert between 8 flow rate units such as L/min, m³/h, US gal/min, and ft³/s. Enter a value, pick a unit, and see every conversion at once.

Convert weight and mass between grams, kilograms, tonnes, pounds, ounces, and more. Enter a value, pick its unit, and see a full conversion table instantly.

Convert between force units such as newtons (N), kilonewtons (kN), kilogram-force (kgf), dynes, and pound-force (lbf). Just enter a value and pick a unit to see all conversions at once.

Quickly estimate how much you can save on yearly electricity and CO2 by replacing incandescent bulbs with LED or fluorescent lamps, based on wattage, hours of use, and the number of bulbs.

Estimate how much fuel money and CO2 you can save each year, and how many calories you'll burn, by replacing your car commute with a bicycle.

Estimate the annual electricity savings, CO2 reduction, and payback period when you replace an old appliance with an energy-efficient model, straight from the power consumption.

Estimate the electricity cost and CO2 emissions of running an AC in cooling mode from its power draw (W), hours, and days. You can also pick by room size.

Estimate the electricity cost and CO2 emissions of running your AC in heating mode, broken down per hour, day, and month.

Estimate the fuel cost and CO2 emissions of a kerosene fan heater from its kerosene use. Enter hourly consumption, hours per day, number of days, and the kerosene price to see the cost and CO2 for the period.

Enter a date of birth to find your exact age in years, plus days until your next birthday and the total number of days you have been alive.

Solve f(x)=0 with the bisection method. Enter a function and an interval to get the approximate root, f(root), the iteration count, and the error, plus a per-step table of intervals and midpoints and a function graph.

A numerical tool that solves your equation f(x)=0 with the false position method (linear interpolation, regula falsi). Enter an interval and a tolerance to get the approximate root, f(root), the iteration count, and a table and chart of the iteration process.

Enter f(x) and its derivative f'(x) as expressions and use Newton's method to find an approximate root of f(x)=0. Includes an iteration table and a convergence chart.

Solve f(x) = 0 with Newton's method. Just enter the equation, initial guess, tolerance, and max iterations - the derivative is approximated automatically by numerical differentiation. Shows the approximate root, f(root), iteration count, error, plus a step table and a graph.

Solve f(x)=0 with Halley's method. Enter the expression, an initial guess, a tolerance, and the iteration limit to get the approximate root, f(root), iteration count, error, an iteration table, and a convergence chart.

Enter dy/dx = f(x, y) with an initial condition and step size, and Euler's method computes the numerical solution. Shows the y value at the end point, a step-by-step table, and a graph of the solution curve.