Macro Calculator
Work out how many calories you need each day, and how to split them between protein, carbohydrate and fat. Fill in five fields and you have a target in under a minute. Add your body fat percentage if you know it and the numbers get sharper again. It is free, there is nothing to sign up for, and nothing you enter leaves your device.
How this calculator works
Your body burns energy even at complete rest, keeping your heart beating and your temperature steady. That figure is your basal metabolic rate, and it is the foundation of everything else.
If you leave the body fat field blank, the calculator estimates your rate from height, weight, age and sex. This is the standard approach and it is accurate to within roughly ten percent for most people.
If you enter a body fat percentage, it switches to an equation that separates lean mass from fat mass and weights them differently, because a kilogram of muscle burns considerably more energy at rest than a kilogram of fat. Two people at the same weight can have genuinely different requirements, and this is where that shows up.
Your basal rate is then multiplied by an activity factor to give total daily energy expenditure. The multipliers here are deliberately conservative. Most calculators are generous, people overestimate how active they are, and the result is a target that quietly stalls progress. It is far easier to add calories to a plan that is working than to explain away one that is not.
Protein is the one macronutrient worth being precise about. It preserves muscle while you are losing weight, it is the most filling of the three, and it costs the most energy to digest. The target here is highest while you are in a deficit, and it rises with age. If you have entered a body fat percentage it is calculated from your lean mass rather than your total weight. Fat has a floor, and carbohydrate takes the rest.
Frequently asked questions
How accurate is a macro calculator? Any equation of this kind estimates your metabolic rate to within about ten percent. Treat the output as a starting point, hold it for two to three weeks, and adjust based on what the scale and the mirror actually do.
Do I need to track macros to lose weight? No. Total energy intake is what drives weight change, and plenty of people manage that without weighing food. Tracking is a tool for learning what your portions actually contain.
Should I enter my body fat percentage? Only if you have a reliable figure from a DEXA scan, a BodPod, or skinfolds taken by someone competent. A guess will make the estimate worse, not better. Left blank, the calculator uses the standard approach.
Are carbohydrates bad for fat loss? No. Carbohydrate intake does not determine fat loss; energy balance does. If you train hard, carbohydrate is what fuels it.
How much protein do I actually need? For someone training regularly, roughly 1.6 to 2.2 grams per kilogram of bodyweight per day covers almost everyone, with the higher end preferable during a calorie deficit.
How often should I recalculate? Every four to six kilograms of weight change, or whenever progress stalls for three weeks straight. Your requirements fall as you get lighter.