Fast · private · browser-only

Understand the estimate—and its limits.

Explore educational estimates for body measurements, energy needs, exercise, pregnancy dates and cycle timing.

Browse tools

Focused utilities

Health and Fitness Calculators

Browser-only

Pregnancy due date

Estimate a pregnancy due date and conception timing from the first day of the last menstrual period.

Open tool Browser-only

Ovulation estimate

Estimate ovulation, a possible fertile window and the next period from cycle dates.

Open tool Browser-only

BMI calculator

Calculate adult body mass index and the corresponding standard screening range.

Open tool Browser-only

BMR and TDEE

Estimate basal metabolic rate and total daily energy expenditure using activity multipliers.

Open tool Browser-only

Calorie deficit

Translate a planning-level weekly weight-change target into an estimated daily energy difference.

Open tool Browser-only

Body fat estimate

Estimate body-fat percentage from circumference measurements using the US Navy method.

Open tool Browser-only

Weight references

Compare the historical Devine reference with weights corresponding to BMI 18.5 and 24.9.

Open tool Browser-only

Macro calculator

Convert a daily calorie total and percentage split into grams of protein, carbohydrate and fat.

Open tool Browser-only

Running pace

Calculate minutes per kilometre, minutes per mile and average speed from distance and finishing time.

Open tool Browser-only

Heart-rate zones

Estimate moderate and vigorous exercise zones from age and resting heart rate.

Open tool Browser-only

One-rep max

Estimate a one-repetition maximum from a submaximal weight and completed repetitions.

Open tool Browser-only

Waist-to-height ratio

Calculate waist circumference as a proportion of height for general screening context.

Open tool Browser-only

Calories burned

Estimate exercise energy expenditure from body weight, activity MET value and duration.

Open tool Browser-only

Sleep duration

Calculate time in bed, estimated sleep duration and approximate cycle count across midnight.

Open tool Browser-only

Water intake estimate

Create a planning estimate from body weight and exercise time with adjustable assumptions.

Open tool

Clear answers

About health and fitness calculators

Are the health and fitness calculators free?

Yes. Every tool in this collection is free to use without an account.

Does MW SysArc receive what I enter?

No. Inputs and calculations remain inside your browser and are not transmitted to or stored by MW SysArc.

Can I use the results for important decisions?

Treat results as practical estimates. Verify consequential academic, employment, financial or access decisions against the applicable rules and source records.