How the weight loss calculator sets your deficit
We estimate your TDEE (the calories you burn in a typical day), then set your target 20% below it. Protein is set first at 2.2 g per kg of bodyweight (about 1 g per lb), fat is 25% of calories, and carbs fill the rest. If your BMI is 30 or above, protein is based on your goal weight or a reference weight for your height instead of total bodyweight, so the target stays realistic. The methodology page shows every formula.
Prefer a gentler start? Take the result and add 5–10% of the calories back. A smaller deficit is slower, but it is easier to keep for months, and consistency matters more than the size of the deficit.
Safe rates: how fast should you lose weight?
A useful starting range is 0.5–1% of bodyweight per week. For a 180 lb (82 kg) person that is roughly 0.9–1.8 lb (0.4–0.8 kg) a week. Enter a goal weight and number of weeks and the calculator shows the weekly pace; if it is faster than 1% of your bodyweight, you will see a warning.
Expect the first week or two to drop faster on the scale. Lower carbs and sodium release stored water and glycogen, which is not fat. Judge your pace on weeks three onward.
Macros for weight loss for women
The method is the same for women and men; the calculator uses a different BMR constant for each. Two things are worth knowing:
- Water swings are normal across a menstrual cycle. Compare the same phase month to month, or use a 7-day average, before deciding a plan has stalled.
- Very low calorie targets are hard to sustain. If the result lands near or below your BMR, use a smaller deficit or add activity instead of eating less.
If you are pregnant, breastfeeding, or have a history of disordered eating, do not use a calorie deficit without guidance from a doctor or registered dietitian.
What to change when weight loss stalls
- Check tracking first: oils, drinks, sauces and weekend meals are the usual gaps.
- Recalculate after every 3–4 kg (7–9 lb) lost, because a smaller body burns less.
- Then cut calories by another 5–10%, or add steps, rather than making a large cut.
- Compare weekly averages and waist measurements for two or three weeks before changing the plan again.
Weight Loss Macro Calculator FAQ
How do I calculate my macros for weight loss?
Estimate TDEE, subtract 10–20%, set protein at 1.6–2.2 g/kg (0.7–1 g/lb), set fat at 20–35% of calories and give the remainder to carbs. The calculator above does this with a 20% deficit.
What should my macro percentage be for losing weight?
A common starting range is 30–40% protein, 30–40% carbs and 25–30% fat, but grams based on bodyweight are more reliable than percentages.
Is a 40/30/30 split good for weight loss?
It can be workable. Check that the protein grams match your bodyweight and that fat is not pushed below about 20% of calories.
Is a macro calculator good for weight loss?
It gives you a useful starting target. Your real weekly weight trend tells you when to adjust.
How many calories should I eat to lose 2 lb a week?
That usually requires a deficit of about 1,000 calories a day, which is too aggressive for many people. A pace of 0.5–1% of bodyweight per week is a safer starting point.
Why did my weight go up after starting a deficit?
Water retention, sodium, a new training load and hormonal shifts can hide fat loss during the first one or two weeks.
Can I lose weight without counting macros?
Yes. Tracking is a precision tool, not a requirement. A consistent calorie deficit is what drives weight loss.
Do I need to exercise to lose weight?
A calorie deficit drives weight loss. Resistance training helps you keep muscle while you lose.
General information only, not medical advice. Talk to a qualified healthcare professional before changing your diet, especially if you are pregnant, breastfeeding, under 18 or managing a medical condition.