FREE TOOLS · CALCULATORS

Free online calculators

Percentages, rule of three, fractions, loans, age, days between dates, BMI, units and time zones, plus a timer, a stopwatch and random draws. Everything is calculated in your browser as you type, and you can copy the result with one tap.

24 free tools
No uploads
No watermark

Numbers and percentages

A calculator with history, percentages in every form, direct and inverse rule of three, fractions step by step and the mean, median or weighted grade.

Online calculatorBasic and scientific, with memory and history.Percentage calculatorX% of Y, what percent, increases and discounts.Rule of threeDirect, inverse and compound, step by step.Average calculatorMean, weighted, median and mode of your grades.Fraction calculatorAdd, subtract, multiply and divide with steps.

Money

Add or remove VAT with the rate you type, work out a loan payment with its amortization table or how savings grow with compound interest. These are estimates: check the current rate.

Loan calculatorPayment, interest and amortization table.VAT calculatorAdd or remove tax, discounts and tips.Compound interestSavings with contributions, table and chart.

Dates and times

Your exact age in years, months and days, the days between two dates (business days too) and the time in another city.

Age calculatorExact age in years, months and days.Days between datesDays, weeks and working days between dates.Time zone converterCompare the time in several cities at once.

Health

BMI, daily calories, weeks of pregnancy and fertile days with the formula each page names. They are rough estimates: they do not replace a health professional.

BMI calculatorBMI with the WHO categories for adults.Calorie calculatorCalories to maintain, lose or gain weight.Pregnancy calculatorWeeks of pregnancy and estimated due date.Ovulation calculatorEstimated ovulation and fertile days per cycle.

Units

Length, weight, temperature, volume, area, speed, data, pressure and energy, from metric to imperial and back.

Unit converterLength, weight, temperature, volume and more.

Timer and stopwatch

A countdown with an alarm, a stopwatch with laps and the Pomodoro technique, which keep time correctly even if you switch tabs.

TimerCountdown with an alarm, even in another tab.StopwatchHundredths of a second, laps and CSV download.PomodoroWork blocks and breaks with an alert.

Draws and chance

Spin a wheel, draw names, flip a coin, roll dice or pick random numbers, with your browser’s cryptographic generator.

Random numberRandom numbers in the range you choose.Spin the wheelSpin a wheel with your names or options.Random name pickerWinners, alternates and random teams.Flip a coinFlip one coin or up to 100 at once.Roll dice1 to 10 dice from 4 to 100 sides, with a sum.

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Calculators: common questions

Are the results accurate?

They use well-known formulas and round at the end to avoid floating-point errors; the health and money ones name their formula on their page. Those give estimates: they do not replace a professional and are not financial advice.

Can I type with a comma or a period?

Yes. You can type 1250.50, 1,250.50 or 1.250,50: the calculator recognizes the separators and shows the result with those of your language.

How do the draws and dice work?

They use your browser’s own cryptographic generator, without bias, and nobody can pick the result. Cocuyo does not see or store what comes up.

Is my data sent to a server?

No. The numbers, dates and names you type are calculated in your browser and are not sent to Cocuyo or to any third party.

Are they free?

Yes. They use no credits, have no usage cap and need no subscription. You can try them before signing up; to keep using them, we ask for a free account.

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