Health & body calculators for everyday questions
Nine calculators for the numbers people look up about their bodies, their sleep, a pregnancy, a new baby and even a pet. They accept US units such as pounds, feet and inches.
When would you use these?
Most health questions start with a number. How much should I weigh for my height? How many calories do I burn at rest? How many hours of sleep fits my schedule? These tools turn a few simple inputs into an answer you can use. Start with the BMI calculator to see where your weight sits for your height, then use the BMR calculator to estimate how many calories your body burns at rest, and the calories burned calculator to see what a workout adds on top.
Sleep and family planning have their own tools. The sleep calculator works in 90-minute cycles so you can pick a bedtime or wake-up time that fits them. If you are expecting, the due date calculator, the pregnancy week calculator and the ovulation calculator cover the dates people ask about most. After the birth, the baby age calculator shows your baby's age in days, weeks and months, with the milestones coming up.
Pet owners are not left out. The dog and cat age calculator turns a pet's years into a human-age equivalent using a size-aware curve rather than the old multiply-by-seven rule. Every tool runs in your browser, so your height, weight and dates stay on your device.
Which tool does what
| Tool | Answers | Useful if you are |
|---|---|---|
| BMI Calculator | Body mass index and weight category, with standard and Asian-American cut-offs | Checking where your weight sits for your height |
| BMR Calculator | Calories your body burns at rest, plus daily calorie targets | Planning calories for weight loss, maintenance or gain |
| Calories Burned Calculator | Calories burned by an activity for your weight and time | Comparing workouts or logging exercise |
| Sleep Calculator | Bedtimes and wake-up times based on 90-minute sleep cycles | Waking up between cycles and feeling less groggy |
| Pregnancy Week Calculator | How many weeks and days pregnant you are, and the trimester | Tracking a pregnancy from your last period or due date |
| Due Date Calculator | Estimated due date from your last period, conception date or IVF transfer | Planning ahead for the birth |
| Ovulation Calculator | Estimated fertile window and ovulation day from your cycle | Timing when trying to conceive |
| Baby Age Calculator | Age in days, weeks and months, and upcoming milestone dates | Parents of newborns and infants |
| Dog & Cat Age Calculator | Your pet's age in human years, by species and size | Understanding your pet's life stage |
Frequently asked questions
Are these calculators medical advice?
No. They give estimates from standard formulas for general information. A doctor or dietitian can interpret the numbers in light of your health, age and history.
Why does the BMI calculator show two sets of cut-offs?
The World Health Organization sets general cut-offs, and some health bodies use lower ones for people of Asian descent because health risks can rise at lower BMI values. Showing both lets you compare.
In what order should I use the weight tools?
Check BMI first for a quick overview, estimate resting calories with BMR next, and then use the calories burned tool to see how activity changes your daily total. Treat all three as starting points, not targets.
How accurate is a due date?
A due date is an estimate. Only a small share of babies arrive on the exact date, and most are born within a couple of weeks either side. Use it for planning and rely on your care team for medical decisions.
Do these tools store my health information?
No. The calculations run in your browser and the numbers you enter are not sent to a server.
Results are for information only and are not a substitute for professional medical advice, diagnosis or treatment.