Every calculation,
clearly explained.
Free, fast online calculators for math, everyday life and conversions — each one shows its formula, its steps and a worked example.
- 33 free calculators
- Steps, not just answers
- Runs in your browser
- No sign-up
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Math Calculators
Percentages, fractions, ratios, averages, exponents and more — every result explained step by step.
Everyday Calculators
Age, dates, GPA, tips, discounts and the practical calculations that come up in daily life.
Statistics Calculators
Mean, standard deviation, variance and other statistical measures — computed step by step from your data.
Finance Calculators
Margin, markup, profit, break-even and sales tax — the pricing maths every business owner needs, explained without jargon.
Unit Converters
Length, weight, temperature, area, volume and speed converters with instant, accurate results.
Popular calculators
View all →Percentage Calculator
Find what X% of a number is, what percent one number is of another, and percentage increase or decrease — with steps.
Fraction Calculator
Add, subtract, multiply and divide fractions. Results are automatically simplified and shown with steps and decimal form.
Ratio Calculator
Simplify ratios to lowest terms or solve for the missing value in equivalent ratios like A:B = C:D.
Proportion Calculator
Solve proportions by cross-multiplication: enter three known values of a/b = c/d and find the fourth instantly, with steps.
Average Calculator
Calculate the mean, median, mode, range and sum of any list of numbers — paste or type your data and get every statistic at once.
Standard Deviation Calculator
Calculate sample or population standard deviation and variance from your data — with the mean, every squared deviation and full steps shown.
Statistics Calculator
Full descriptive statistics for any data set: mean, median, mode, quartiles, IQR, variance, standard deviation, standard error and more.
T-Test Calculator
Run a one-sample, two-sample (Welch) or paired t-test: get the t statistic, degrees of freedom and two-tailed p-value with interpretation.
Rounding Calculator
Round any number to the nearest whole number, tenth, hundredth, thousandth or any decimal place — with the rounding rule explained.
Square Root Calculator
Find the square root of any number, including simplified radical form for whole numbers (√48 = 4√3) and step-by-step working.
Exponent Calculator
Calculate powers like 2⁸ or 5⁻³, including negative and fractional exponents, with the exponent rules explained.
GCF and LCM Calculator
Find the greatest common factor and least common multiple of two or more numbers, with prime factorizations shown.
Scientific Calculator
Free online scientific calculator with trig (degrees or radians), logarithms, powers, roots, π and parentheses — keyboard friendly.
Matrix Calculator
Add, subtract and multiply matrices up to 5×5, and find the determinant, inverse and transpose — with dimension rules explained.
Age Calculator
Calculate exact age in years, months and days from a date of birth, plus total days lived and days until your next birthday.
Date Difference Calculator
Count the days, weeks, months and years between any two dates — for deadlines, events, projects and anniversaries.
Tip Calculator
Work out the tip and total for any bill, split evenly between any number of people — with common tipping percentages explained.
Discount Calculator
Find the sale price and savings for any discount, including stacked double discounts like an extra 20% off a 30%-off price.
Random Number Generator
Generate one or many random numbers in any range — whole numbers or decimals, with or without repeats.
Time Calculator
Add or subtract hours, minutes and seconds — get the total as clock time and as decimal hours for timesheets.
Grade Calculator
Work out your weighted course grade from assignments and exams — and the score you need on the final to hit your target.
GPA Calculator
Calculate your grade point average on the 4.0 scale from course grades and credit hours — add as many courses as you need.
Margin Calculator
Calculate profit margin, markup, cost, selling price or profit — enter any two values and get the rest, with steps, currency and quantity totals.
Markup Calculator
Work out markup percentage from cost and price, or the price to charge for a target markup — and see the margin it produces.
Profit Calculator
Calculate gross profit, net profit and profit margin from revenue, cost of goods and operating expenses — for one sale or a whole period.
Break-Even Calculator
Find the units and revenue you need to cover your costs, from fixed costs, price per unit and variable cost per unit — plus your margin of safety.
Sales Tax & VAT Calculator
Add tax to a net price or strip tax out of a gross price — works for US sales tax, UK/EU VAT and GST, with the tax amount shown separately.
Length Converter
Convert between millimeters, centimeters, meters, kilometers, inches, feet, yards and miles — instantly and exactly.
Weight Converter
Convert between grams, kilograms, metric tons, ounces, pounds and stone with exact international definitions.
Temperature Converter
Convert between Celsius, Fahrenheit and Kelvin with the exact formulas shown — plus a reference table of everyday temperatures.
Area Converter
Convert between square meters, square feet, square yards, acres, hectares and square kilometers.
Volume Converter
Convert between milliliters, liters, cubic meters and US cups, fluid ounces, pints, quarts and gallons — perfect for cooking and more.
Speed Converter
Convert between miles per hour, kilometers per hour, meters per second, knots and feet per second.
Why CalculatorsGuide?
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