Life & Health Calculators
Calorie Calculator
Find how many calories to eat per day to lose, maintain, or gain weight, with targets for each goal rate.
BMI & TDEE Calculator
Calculate your Body Mass Index and Total Daily Energy Expenditure for fitness and diet planning.
Date & Business Days Calculator
Calculate days between dates, add or subtract days, and count business days excluding weekends.
Random Picker Wheel
Spin a colorful wheel to randomly pick a name or winner. Supports weighted items for custom probabilities. Great for teachers, streamers, and group events.
Shoe & Clothing Size Converter
Convert shoe and clothing sizes between US, UK, EU, and JP standards. Charts for men, women, and kids.
BMR & Ideal Weight Calculator
Calculate your Basal Metabolic Rate and ideal body weight using four medical formulas. Compare Devine, Robinson, Miller, and Hamwi methods.
Pregnancy Due Date & Ovulation Calculator
Calculate your estimated due date from your last period, track pregnancy week by week, and find your fertile ovulation window.
Age Calculator
Calculate your exact age in years, months, and days. See total months, weeks, hours lived, plus zodiac sign and birthstone.
Timer & Stopwatch
Online countdown timer and stopwatch with alarm, presets, and laps. Keeps accurate time in background tabs and survives reloads.
Ovulation & Period Calculator
Estimate your ovulation day, fertile window, and next period date based on your cycle length and last period.
Body Fat Calculator
Estimate your body fat percentage using the US Navy method or BMI-based formula. See lean mass, fat mass, and fitness category.
Sleep Calculator
Find the best time to sleep or wake up based on 90-minute sleep cycles, so you wake up refreshed.
Pomodoro Timer
A customizable Pomodoro timer with work, short break, and long break phases. Track focus sessions and boost productivity.
Running Pace Calculator
Calculate your running pace, speed, and predicted race times. View per-km or per-mile splits for any distance.
Recipe Multiplier / Divider
Scale recipe ingredients up or down by servings. Paste your ingredient list, adjust portions, and get recalculated amounts instantly.
Split Bill & Tip Calculator
Calculate the total amount with tip and exactly split the bill among any number of people.
Water Intake Calculator
Calculate your recommended daily water intake based on body weight, activity level, and climate. Stay hydrated with personalized guidance.
Grade Calculator
Quickly grade a test by questions and wrong answers (EZ grader), or work out the score you need on your final exam.
GPA Calculator
Calculate your Grade Point Average (GPA) using a standard 4.0 or 4.3 scale based on your course grades and credits.
Life & Health Calculators
Nineteen calculators for the arithmetic that comes up in ordinary life, what to eat, when to sleep, how long until a due date, what score you need on a final. Health figures here are estimates from published formulas, not medical advice, and each page names the formula it uses so you can see where a number came from. Nothing you enter is transmitted; the calculations happen in your browser.
Body Composition and Energy
The BMI & TDEE calculator gives your body mass index alongside total daily energy expenditure, which is the figure most diet planning starts from. The BMR & ideal weight calculator isolates basal metabolic rate, what you burn at rest, and compares four ideal-weight formulas (Devine, Robinson, Miller, Hamwi) rather than presenting one as definitive, because they disagree by several kilograms. The body fat calculator estimates composition by the US Navy circumference method or from BMI, and reports lean and fat mass separately. Once you know your expenditure, the calorie calculator converts it into a daily intake target for losing, maintaining, or gaining weight at a chosen rate, and the water intake calculator adjusts a daily fluid figure for body weight, activity, and climate.
Training, Focus, and Rest
The running pace calculator converts between pace and speed, predicts finish times for standard distances, and prints per-kilometre or per-mile splits. The sleep calculator works backwards from a wake time in 90-minute cycles, so you wake between cycles rather than in the middle of one. For work rather than exercise, the Pomodoro timer runs configurable focus and break phases and counts completed sessions, while the timer & stopwatch handles plain countdowns and laps, and keeps accurate time in a background tab and across reloads, which most browser timers do not.
Cycle and Pregnancy
The ovulation & period calculator estimates your fertile window and next period from cycle length and last period date. The pregnancy due date calculator takes it forward, estimating a due date and tracking the pregnancy week by week.
School and Scores
Two tools cover grades, and they answer different questions. The grade calculator works at the level of a single test, mark it by questions and wrong answers like an EZ grader, or find the score you need on a final to reach a target. The GPA calculator works across a semester, weighting course grades by credits on a 4.0 or 4.3 scale.
Everyday Arithmetic
The age calculator gives an exact age in years, months, and days, plus totals in weeks and hours. The date & business days calculator counts the span between two dates or adds days to one, and can exclude weekends when a deadline is quoted in working days. The split bill & tip calculator divides a total with tip across any number of people. The recipe multiplier rescales a pasted ingredient list to a different number of servings. The shoe & clothing size converter maps between US, UK, EU, and JP sizing for men, women, and children, useful before ordering from an overseas store. And the random picker wheel draws a name at random, with optional weights when the entries should not have equal odds.