Family, Health & Culture
Due date, dog age, water intake, calendar converters (Hijri, Hebrew, Chinese), color palettes and contrast checker – helpful everyday tools, free.
A due date calculator, pregnancy week calculator and ovulation calculator, BMI calculator, water intake and calories burned, dog age and cat age, calendar converters (Hijri, Hebrew, Chinese, Persian) and Ramadan dates, plus color palettes, a color converter and a contrast checker. Health figures are estimates with sources and do not replace medical advice.
27 tools
- BMI calculator (WHO categories)Calculate your body mass index in lb and ft/in or kg and cm. See your WHO category, from underweight to obesity class III, and the healthy weight range.
- BMR and daily energy needs calculatorCalculate your basal metabolic rate with the Mifflin-St Jeor equation and your total daily energy needs with FAO/WHO activity levels (PAL), in kcal and kJ.
- Body Fat Calculator (U.S. Navy Method)Estimate your body fat percentage from height, neck, waist and hip measurements using the U.S. Navy equations by Hodgdon and Beckett (1984). In inches or cm.
- Calories burned calculatorEstimate calories burned in 30 sports and activities from MET value, body weight and duration per the 2024 Compendium, in kg or lb, with a personal correction.
- Cat age calculator: cat years to human yearsHow old is my cat in human years? Convert cat age, kittens in months too, with the AAFP-AAHA chart and see the life stage from the 2021 AAHA/AAFP guidelines.
- Chinese Calendar Converter and Zodiac SignConvert a date to the Chinese lunar calendar and back: year in the 60-year cycle (Heavenly Stem, Earthly Branch), zodiac animal, element, New Year.
- Color contrast checker (WCAG 2.2)Check the contrast between text and background colors: WCAG 2.2 contrast ratio with AA/AAA ratings for normal text, large text and UI components.
- Color converter: HEX, RGB, HSL, HSV, CMYKConvert color codes: HEX to RGB, RGB to HEX, HSL, HSV, HWB and CMYK – type any format or use the color picker and copy the result, right in your browser.
- Color palette generatorBuild matching colors from one base color: complementary, analogous, triadic, square, split-complementary or monochrome – with HEX, RGB and HSL values.
- Color picker from image (eyedropper)Get color codes from any image: open a photo, click a spot and copy the HEX, RGB or HSL value – plus the main colors. No upload, it all stays in your browser.
- Dog age calculator: dog years to human yearsHow old is your dog in human years? Uses the 16·ln(age)+31 formula (Wang et al. 2020) and the AVMA size chart, compares both and shows the senior age.
- Due Date CalculatorEstimate your due date from the last menstrual period (with cycle length) or conception date – plus current pregnancy week, trimester and days to go.
- Heart Rate Zone CalculatorCalculate your training heart rate zones: enter your max heart rate or estimate it with Tanaka, then get zones as % of max HR or with the Karvonen method.
- Hebrew Date Converter (Jewish Calendar)Convert a Gregorian date to the Jewish (Hebrew) calendar and back – with month names, leap years (Adar I/II) and the date of Rosh Hashanah.
- Hijri Date Converter (Islamic Calendar)Convert a Gregorian date to the Islamic Hijri calendar and back – using Umm al-Qura (Saudi Arabia) or the tabular calendar, with month length.
- Ideal weight calculator: your healthy weight rangeFind your healthy weight range from your height: the weights that give a BMI of 18.5 to 24.9 (WHO), in lb and kg – instead of one questionable ideal number.
- One Rep Max (1RM) CalculatorEstimate your one-rep max from weight and reps using the Epley and Brzycki formulas, with a %1RM chart for 1 to 10 reps. Works in kg or lb.
- Ovulation Calculator: Estimate Your Fertile WindowEstimate ovulation and your fertile window with the calendar method for the next 3 cycles. An estimate only – this is not a method of contraception.
- Persian Calendar Converter (Solar Hijri)Convert a Gregorian date to the Persian calendar (Solar Hijri, Jalali) and back – with month names, leap years and the date of Nowruz, the Persian New Year.
- Pregnancy Week CalculatorHow many weeks pregnant am I? Work out your pregnancy week from the last period or due date – weeks and days, trimester, month and days until the due date.
- Race time predictor (Riegel formula)Predict your finish time for 5K, 10K, half marathon, marathon or any distance from a recent race result, using Riegel’s formula, with pace per km and mile.
- Ramadan Calendar: Start and End DatesWhen is Ramadan? Start, last day of fasting and Eid al-Fitr for 2025 to 2035, calculated with the Umm al-Qura calendar – with a note on moon sighting.
- Running pace calculatorCalculate running pace per km or mile, finish time or distance. With speed in km/h and mph, splits per km or mile and times for 5K, 10K, half and marathon.
- Sleep Cycle CalculatorSleep calculator: what time to go to bed if you wake up at 7 am, or when to set the alarm. 4 to 6 sleep cycles of about 90 minutes as a rule of thumb.
- Convert Steps to KilometresConvert steps to km and miles: how far is 10,000 steps? Uses your own step length – also converts a distance in km into steps.
- VO2 Max Calculator (Cooper Test)Estimate your VO2max from the 12-minute run: enter the distance in meters or miles and get ml/kg/min using the Cooper equation (JAMA 1968).
- Daily water intake calculatorHow much water should you drink a day? Daily fluid and total water intake by age, sex, pregnancy and breastfeeding, based on EFSA and German DGE values.