Free Online Calculators
Calculator Tools focus on accurate, transparent math for everyday decisions: shopping discounts, health metrics, loan estimates and date planning. Each calculator uses a reusable engine so results stay consistent and testable.
41
tools in this category
Popular calculators tools
Frequently opened tools in this category.
6 tools
Age CalculatorCalculate exact age from a date of birth. See years, months and days instantly: free and private in your browser.BMI CalculatorCalculate Body Mass Index from height and weight. See BMI value and standard category ranges: free and private.Date CalculatorCalculate the number of days between two dates, or add/subtract days from a start date. Free date difference tool.Discount CalculatorCalculate sale price after a discount, or find the percent off from original and final prices. Free shopping math.Percentage CalculatorCalculate percentages online: what is X% of Y, what percent is X of Y, and percent increase or decrease.Time CalculatorCalculate time duration between two times, or add and subtract hours and minutes. Free time difference tool.
Finance
Loans, interest, tax, and money math.
13 tools
Discount CalculatorCalculatorCalculate sale price after a discount, or find the percent off from original and final prices. Free shopping math.Compound Interest CalculatorCalculatorFuture value with annual, monthly, daily and other compounding frequencies.Currency ConverterCalculatorConvert currencies with a static rate table plus optional Frankfurter live rates.EMI CalculatorCalculatorEquated monthly installment from principal, annual rate and tenure in months.GST CalculatorCalculatorGoods and services tax calculator for inclusive or exclusive amounts.Investment CalculatorCalculatorGrow a starting principal with optional monthly contributions.Loan CalculatorCalculatorEstimate monthly loan payments, total interest and total cost over the term.Profit Margin CalculatorCalculatorProfit and margin percent from cost and revenue.Salary CalculatorCalculatorConvert annual, monthly and hourly pay with a standard 40×52 work year.Sales Tax CalculatorCalculatorAdd or extract sales tax with net, tax and gross amounts.Simple Interest CalculatorCalculatorCompute simple interest and maturity amount with PRT/100.Tip CalculatorCalculatorTip amount, bill total and per-person split for restaurants.VAT CalculatorCalculatorAdd or extract VAT at a custom rate with net, tax and gross.
Date & Time
Age, dates, time zones, and calendars.
13 tools
Age CalculatorCalculatorCalculate exact age from a date of birth. See years, months and days instantly: free and private in your browser.Date CalculatorCalculatorCalculate the number of days between two dates, or add/subtract days from a start date. Free date difference tool.Percentage CalculatorCalculatorCalculate percentages online: what is X% of Y, what percent is X of Y, and percent increase or decrease.Time CalculatorCalculatorCalculate time duration between two times, or add and subtract hours and minutes. Free time difference tool.Average CalculatorCalculatorMean, median, sum and range from a list of numbers.Business Days CalculatorCalculatorBusiness days excluding Saturday and Sunday between two dates.Date Difference CalculatorCalculatorFull date span with days, weeks, approximate months/years and business days.Days Between DatesCalculatorExact calendar day count between two dates.Percentage Decrease CalculatorCalculatorCalculate percentage decrease for markdowns, losses and declining metrics.Percentage Increase CalculatorCalculatorCalculate percentage increase between two values with clear growth percent.Time Difference CalculatorCalculatorElapsed duration between two clock times with overnight support.Time Duration CalculatorCalculatorNormalize hours, minutes and seconds into a readable duration.Working Days CalculatorCalculatorCount Monday–Friday working days between two dates.
Health
BMI, calories, and body metrics.
3 tools
BMI CalculatorCalculatorCalculate Body Mass Index from height and weight. See BMI value and standard category ranges: free and private.BMR CalculatorCalculatorBasal metabolic rate with Mifflin-St Jeor from weight, height, age and sex.Calorie CalculatorCalculatorDaily calorie targets from Mifflin-St Jeor BMR and activity level.
Math
Percentages, units, grades, and formulas.
6 tools
Fraction CalculatorCalculatorAdd, subtract, multiply or divide fractions and simplify the result.GPA CalculatorCalculatorWeighted GPA on a 4.0 scale from letter grades and credit hours.Grade CalculatorCalculatorFind the score needed on remaining work to hit a target grade.Ratio CalculatorCalculatorSimplify a:b ratios and show the decimal equivalent.Scientific CalculatorCalculatorSafe expression calculator with powers and trig: no eval().Unit ConverterCalculatorConvert length, mass and temperature across common metric and imperial units.
Business
Invoices, margins, and break-even math.
2 tools
More tools
Additional utilities in this category.
4 tools
Electricity Cost CalculatorCalculatorEstimate electricity spend from kWh usage and rate per kWh.Fuel Cost CalculatorCalculatorTrip fuel used and cost from distance, L/100km and price per litre.Probability CalculatorCalculatorProbability, percent and odds from favorable and total outcomes.Savings CalculatorCalculatorProject savings with monthly deposits and monthly compounding.
How it works
- 01
Open the calculator you need.
- 02
Enter your values in the form.
- 03
Review the result and any explanatory breakdown.
- 04
Adjust inputs to compare scenarios instantly.