Weight loss calculator
How long until you reach your goal? An honest date range, not one magic day – with a safe calorie minimum. No sign-up.
~28–31 weeks
Eat about 1690 kcal a day · ≈ 0.4 kg a week at first
Where you could be after…
- 83.5kg · 1 month
- 80.1kg · 3 months
- 75.5kg · 6 months
- 75.0kg · 12 months
How we worked it out
- Calorie needs use the Mifflin–St Jeor formula and your activity (the same one our nutrition quiz and app use).
- Every week we work your needs out again at the new weight: the less you weigh, the less your body needs, so the pace slows down.
- The earlier date assumes you update your calorie target every 4 weeks; the later one, that you keep eating the first amount. 1 kg ≈ 7,700 kcal.
- In the first week the scale often drops faster (mostly water) – we left that out. Real life has holidays, colds and plateaus, so the real date is often later still.
How we calculate
First we work out how many calories your body uses a day (the Mifflin–St Jeor formula and your activity) and suggest a target: gentle pace – about 300 kcal less, steady pace – up to 20 % less (no more than 550 kcal). We never plan below the safe minimum. It's the same formula as our calorie calculator and nutrition quiz.
Then we "lose" the weight week by week, working your needs out again at each new weight. The less you weigh, the less your body needs, so the pace naturally slows – which is why the last kilos are the slowest. We count 1 kg of body fat as about 7,700 kcal.
What the calculator doesn't know
- Week-one water. At first the scale often shows 1–2 kg less, mostly water. We left that out so the date isn't too optimistic.
- Daily ups and downs. Weight can swing ±1–2 kg in a day. Watch the weekly average.
- Life. Holidays, colds, stress, poor sleep. Plateaus are normal.
More on a realistic pace: how much weight can you lose in a month.
Frequently asked questions
How long does it take to lose 10 kg?
At a safe pace (roughly 0.3–0.5 kg a week) it usually takes half a year or more, up to a year, depending on your starting weight, height, activity and the pace you choose. The scale often drops faster in week one, but that's mostly water. The calculator above shows your own range.
Why a range of dates instead of one date?
Because one date wouldn't be true. The less you weigh, the fewer calories your body needs, so the pace slows. The earlier date assumes you update your calorie target every few weeks; the later one, that you keep eating the same amount. Real life adds holidays and plateaus on top.
Can I lose weight faster?
Very low calories make the scale move more at first, but part of that is water and muscle, and the hunger and tiredness often end with the weight coming back. That's why we never plan below a safe minimum: the higher of 1,200 kcal for women / 1,500 kcal for men and your basal metabolic rate.
Why can't I choose a very low goal weight?
A goal below a BMI of 18.5 for your height is below the weight recommended for health. We don't make plans for that.
Why do you ask about diabetes, pregnancy and eating disorders?
In those cases changes to what you eat should be agreed with a doctor, so we don't show numbers. These are the same safety rules as in our calorie calculator and app.