What the Fat Grams Per Pound Lost Calculator does
This tool converts the amount of body fat you have lost, or plan to lose, from pounds into grams. A pound of fat weighs the same as any other pound: exactly 453.59237 grams, because the international avoirdupois pound is defined as 0.45359237 kilograms. Enter your pounds and the calculator returns the total grams of fat, the equivalent in kilograms, and, if you add a timeframe, the average grams of fat lost per day.
How to use it
Type the number of pounds of fat you have lost or want to lose into the first field. Optionally, add a timeframe in days to see the average grams-per-day rate over that period. The result shows the total grams, the kilogram equivalent, the fixed grams-per-pound constant, and the daily rate whenever a timeframe is supplied. Leave the pounds field blank and the calculator simply waits for your input rather than guessing.
The formula explained
The conversion rests on the exact definition of the pound. Let p be the pounds of fat and g the grams of fat:
$$g = p \times 453.59237$$If you supply a timeframe of d days, the average grams of fat lost per day, r, is:
$$r = \dfrac{g}{d}$$The value 453.59237 grams per pound is exact by definition, so the total is a direct unit conversion rather than an estimate.
Worked example
Suppose you lost 10 pounds of fat over 30 days. The total grams of fat is 10 times 453.59237, which equals 4,535.92 grams, or about 4.536 kilograms. Dividing that by 30 days gives an average of 4,535.92 divided by 30, roughly 151.2 grams of fat lost per day.
Frequently asked questions
How many grams are in one pound of fat? Exactly 453.59237 grams, the same as any pound, because the pound is defined as 0.45359237 kilograms.
Is a pound of body-fat tissue pure fat? No. Adipose tissue is roughly 87 percent lipid with the rest water and protein, so a pound of tissue holds about 395 grams of pure stored fat. That partial-lipid content is why a pound of fat stores close to 3,500 kilocalories.
Does the grams-per-pound value ever change? No. The 453.59237 grams-per-pound figure is a fixed unit-conversion constant; only the pounds you enter change the total grams.
