Free health and family calculators, with the science shown
Work out your maintenance calories, a safe calorie deficit, macros, BMI and body fat, running pace and heart rate zones, the best time to sleep, a due date or fertile window, and your dog’s age in human years.
- Formulas and sources on every page
- Your numbers stay on your device
- No sign-up, no limits
All tools
11 tools, all free, all private
Energy and nutrition
4 tools
Body and training
4 tools
Family
3 tools
Popular shortcuts
One-click versions of the tools above
Why people use VitalsNook
The science shown
Every result names its formula and the published source behind it, so you can check the working.
Private by design
Your weight, dates and measurements stay on your device. Nothing is sent, stored or put in the page address.
Honest estimates
Ranges instead of false precision, safe limits on weight-loss targets, and plain notes on what each number can’t tell you.
For energy and nutrition
Find your maintenance calories with the TDEE calculator or your resting burn with the BMR calculator, set a safe target with the calorie deficit calculator, and split it up with the macro calculator and the protein calculator. Check your BMI and what it does and doesn’t tell you.
For training and rest
Estimate your body fat with a tape measure, plan a race with the pace calculator, train in the right heart rate zones, and find a bedtime that fits your sleep cycles with the sleep calculator.
For family and pets
Estimate a due date or when conception likely happened, see your fertile window, and turn dog years or cat years into human years.
Frequently asked questions
Something else? Email hello@vitalsnook.com.
Is VitalsNook free?
Yes. Every calculator is free to use as often as you like, with no sign-up. We are supported by ads, which we keep away from the calculators themselves.
Is my information stored or shared?
No. Everything is worked out by your browser on your own device. We don’t keep your numbers or dates, and they never go into the page address unless you choose Copy link to share a calculation. Dates of periods and pregnancies are never put in a link at all.
Can I rely on these results?
They are careful estimates from published formulas, with their limits explained, but they are not medical advice. Bodies vary. For decisions about your health, pregnancy or your pet, talk to your doctor, midwife or vet.