How Long Does It Take to Lose 10 kg (or 20 Pounds)?

By the DietX team · Updated November 4, 2026 · 6 min read

At the 0.5 to 1 kg a week the NHS suggests aiming for, losing 10 kg takes about 10 to 20 weeks. By the same measure, 5 kg takes 5 to 10 weeks, and 20 pounds takes 10 to 20 weeks at 1 to 2 lb a week. These are guides: results vary, and weight loss tends to slow down over time.

How long does it take to lose 5, 10, 15 or 20 kg?

If you think in pounds, at 1 to 2 lb a week:

There's a good reason to stay in that range. The CDC notes that people who lose weight gradually and steadily, at about this pace, are more likely to keep it off.

What pace does your calorie deficit really give you?

The tables above assume you hit the pace. Whether you do depends on your deficit, the gap between what you burn and what you eat. An old shortcut says 3,500 kcal equals about 1 lb of body weight, which gives this:

This shows something the neat tables hide. By this estimate, a moderate deficit of 300 to 500 kcal puts you below the slow end of the 0.5 to 1 kg range, and that's fine. Slower is a perfectly good way to lose weight.

A bigger deficit isn't open to everyone. Someone who maintains on 1,920 kcal would land at 1,170 kcal with a 750 kcal deficit, below the roughly 1,200 kcal level where you should get medical advice. Someone who maintains on 2,800 kcal would land at 2,050 kcal. Our guide to the calorie deficit shows how to size yours.

Why weight loss slows down over time

The 3,500 kcal shortcut assumes every week is the same. Research on energy balance shows they aren't, and that the shortcut overpromises over the long term. Three things are going on:

• Your needs fall as you get lighter. With the standard formula, a woman on a light activity level who loses 10 kg has a maintenance about 138 kcal lower. If she keeps eating the same amount, a 400 kcal deficit has become about 262 kcal.
• Body weight responds slowly. The same research puts the half time at about 1 year. In plain words, if you make a lasting change to what you eat and hold it, about half of the eventual weight change arrives in roughly the first year, and the rest comes more and more slowly.
• Starting size matters. People with more body fat lose more for the same change in intake, and take longer to level off.

The early weeks can also flatter you, since some of the first drop on the scale is often water rather than fat. If you'd like a more personal projection than a table can give, the US National Institutes of Health has a simulator, the Body Weight Planner.

What real programs show

Averages from real people are a useful reality check. In one 6-month program of 1,685 adults, the mean loss was 5.8 kg. That's about 0.2 kg a week averaged over 26 weeks, slower than the tables above. Individual results varied, and behaviors such as keeping food records and being active accounted for most of that variation.

So if you're losing more slowly than 0.5 kg a week, you're in plenty of company. That average came from one program and won't predict your own result, but it's a useful check if you were expecting 1 kg every week.

Plateaus are normal

Expect weeks when nothing moves. Water, salt, gut contents and your cycle can all hide a week or two of real loss, and our guide to why your weight fluctuates explains how to read through that. Weight also tends to rise on weekends and fall during the week, so judging a Monday against a Friday will mislead you.

A stall of a week or two needs no action. If your weekly average has stayed flat for two to three weeks or more, something may have shifted, and our checklist for when you're in a deficit but not losing weight will help you find it. Recalculate your target every few kilos too, because the one you started with gets out of date.

What if you have a deadline?

A wedding or a holiday doesn't change the math. Six weeks at 0.5 to 1 kg a week is 3 to 6 kg, and that's the most it makes sense to plan for. Squeezing more in means crash dieting, which is hard to sustain and can be harmful. So pick the amount that fits the time you have, and keep going afterward if you still want to.

How to plan your own timeline

1. Pick the amount. Say 8 kg.
2. Divide by 1 and by 0.5. That gives 8 to 16 weeks.
3. Add real life. With two holiday weeks at maintenance, call it 10 to 18 weeks.
4. Set your calorie target. Start from how many calories you need a day, then subtract your deficit.
5. Track a weekly average and judge your progress every two to three weeks, not every morning.
6. Recalculate every few kilos, or when your activity changes.

The habit behind a timeline is keeping track. A review of 22 studies consistently linked self-monitoring with weight loss, although the authors called the evidence weak because of limits in how the studies were run. DietX can help with that part: it sets a daily target from your age, height, weight, activity level and goal, lets you log food by photo, description, voice or barcode, and follows your weight and trends over time. It's free to download with a free trial, and Premium is a subscription.

Frequently asked questions

Sources

1. NHS: Tips to help you lose weight
2. CDC: Steps for losing weight
3. Hall et al. (2011), Lancet: Quantification of the effect of energy imbalance on bodyweight
4. NIDDK: Body Weight Planner
5. Hollis et al. (2008), Am J Prev Med: Weight loss during the Weight Loss Maintenance trial
6. Orsama et al. (2014), Obes Facts: Weight rhythms across the week
7. NHS: Eating disorders
8. Burke et al. (2011), J Am Diet Assoc: Self-monitoring in weight loss, a systematic review

General information, not medical advice. Talk to a doctor or dietitian before changing your diet, especially if you are pregnant, under 18 or have a health condition. If tracking food makes you anxious or you have a history of disordered eating, please skip calorie counting and ask a professional for support.