How we calculate

BMI

BMI = weight in kg divided by height in metres squared. With pounds and inches, BMI = 703 x pounds / inches squared. Bands: under 18.5, 18.5 to 24.9, 25 to 29.9 and 30 or more.

Resting energy (BMR)

Mifflin and St Jeor. Men: 10 x kg + 6.25 x cm - 5 x age + 5. Women: 10 x kg + 6.25 x cm - 5 x age - 161.

Daily energy (TDEE)

Resting energy times an activity factor: 1.2 mostly sitting, 1.375 light, 1.55 moderate, 1.725 very active, 1.9 extremely active.

Calorie targets and floors

Target = TDEE plus an aim: keep 0, lose slowly minus 550 kcal, gain slowly plus 300 kcal, or a chosen deficit of 300 or 550. Rounded to the nearest 50 kcal and never below 1,200 kcal for women or 1,500 kcal for men. 550 kcal a day is a rule of thumb for about 0.5 kg a week, not a promise.

Protein

Reference amount per kg: men 0.84 (1.07 over 70), women 0.75 (0.94 over 70). A commonly used higher figure for people who train is 1.6 g per kg. Grams = per kg x body weight.

Macros

Grams = daily kcal x share / kcal per gram, with 4 kcal per gram of protein and carbohydrate and 9 per gram of fat. Shares must add to 100.

Kilojoules

1 kcal = 4.184 kJ. kJ = kcal x 4.184 and kcal = kJ / 4.184.

Water

Adequate intake of fluids from drinks for adults: men 2,600 mL and women 2,100 mL a day (total water including food is higher: 3.4 L and 2.8 L). Glasses = amount / glass size. 1 US fluid ounce = 29.5735 mL.

Sleep

A cycle is taken as 90 minutes and falling asleep as 15 minutes. Bedtime = wake time minus the cycles minus 15 minutes. These are rules of thumb.

Streaks

A day counts if the habit was done. The current streak counts back from today, or from yesterday if today is not done. The longest streak is the longest run of days. A missed day resets the run unless it is a rest day.

What we do not do

We do not store what you enter, and we do not offer medical advice. The sources page lists where the figures come from.

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