How Long Does It Take to Lose a Stone? The Honest Maths

How long does it take to lose a stone? For most people, somewhere between 7 and 14 weeks, depending on how big a calorie deficit you can keep up and how much you have to lose. A stone is 6.35kg, and at a realistic rate of 0.5-1kg a week, the maths lands in that range.

That answer is less exciting than "lose a stone in 3 weeks", but it is the one that tends to stay off. Below I show the numbers, explain why the scale rarely moves in a straight line, and give you a simple plan to follow.

The maths behind losing a stone

A commonly used estimate is that 1kg of body fat stores about 7,700 calories. I explain where that number comes from, and its limits, in my post on how many calories are in 1kg of fat.

Using that figure:

• 6.35kg x 7,700 = roughly 49,000 calories to lose a stone of fat.
• A daily deficit of 500 calories is 3,500 a week, so about 14 weeks.
• A daily deficit of 750 calories is about 5,250 a week, so about 9-10 weeks.
• A daily deficit of 1,000 calories is 7,000 a week, so about 7 weeks.

These are estimates. Your body adapts a little as you lose weight, and day-to-day water changes hide fat loss. But the maths gives you a sensible expectation, which is half the battle.

How long does it take to lose a stone at different weekly rates?

The NHS describes losing about 0.5-1kg a week as a safe, realistic target for most adults. Here is how that plays out for one stone:

• 0.5kg a week: about 13 weeks. Good for people with less to lose, or who want a gentler approach.
• 0.75kg a week: about 8-9 weeks. A solid middle ground for most of my clients.
• 1kg a week: about 6-7 weeks. More realistic if you have a lot of weight to lose, and harder to sustain.

Why the first week often looks faster

When you cut calories and reduce processed food, you usually store less carbohydrate and water. That can mean 1-2kg drops quickly in week one. It is real weight, but much of it is not fat, so do not expect that pace to continue.

Why it slows down later

As you get lighter, you burn slightly fewer calories, and many people move less without noticing. If progress stalls for 2-3 weeks, check your portions and daily steps before cutting food further. My post on why you are not losing weight covers the common causes.

A simple 10-week plan to lose a stone

This plan aims for about 0.6-0.75kg a week. Adjust it with your GP's advice if you have a medical condition, are pregnant or take medication.

Step 1: set your calories

Estimate your maintenance calories and take off around 500-750 a day. My guide to a calorie deficit in the UK walks you through the calculation with everyday food examples.

Step 2: hit your protein

Build every meal around a protein source, like chicken, fish, eggs, Greek yoghurt, beans or tofu. Protein helps you stay full and protects muscle while you diet.

Step 3: lift weights 2-3 times a week

Strength training helps make sure the weight you lose is mostly fat, not muscle. The UK Chief Medical Officers recommend strength work on at least 2 days a week. See my guide to weight training for fat loss for a starting routine.

Step 4: walk more

Daily steps are one of the easiest ways to increase calories burned without feeling wrecked. Aim to add 2,000-3,000 steps to your current average. Here is more on how many steps a day to lose weight.

Step 5: track the right things

• Weigh yourself 3-7 mornings a week and look at the weekly average, not single days.
• Measure your waist every 2 weeks.
• Take photos every 4 weeks.

What a typical week looks like

• Monday: full body strength session, 8,000+ steps.
• Tuesday: 30-45 minute brisk walk, normal meals.
• Wednesday: strength session, quick check of your weekly average.
• Thursday: walk or light cardio.
• Friday: strength session or active rest.
• Weekend: plan one meal out and keep the rest of the day lighter, a long walk on Saturday or Sunday.

Over the week, that also covers the UK guidance of at least 150 minutes of moderate activity.

Can you lose a stone faster?

Some people do, especially at higher body weights. But very large deficits make you hungrier, more tired and more likely to lose muscle, and most crash diets end with the weight coming back. Very low calorie diets should only be done with medical supervision.

A faster, safer option is better structure rather than less food: a clear calorie target, regular strength training, more daily movement and someone checking in. That is how my 12-Week Body Transformation works. Clients lose 6-16kg in 12 weeks (average, results vary) and build 1.2-3kg of lean muscle, measured on InBody scans every 4 weeks.

Want help with this? If you want to lose your first stone with a plan built around your job and your week, I offer 1-to-1 training with a nutrition plan and weekly check-ins. Book a free consultation, or read more about my weight loss personal training.

Frequently asked questions

Can you lose a stone in a month?

It is possible for some people with a lot to lose, but for most, 6.35kg in four weeks would need a very large deficit of around 1,700 calories a day. Part of the early drop is water. A more realistic target for a month is 2-4kg, with the rest of the stone following over the next few weeks.

How many calories should I eat to lose a stone?

There is no single number, because it depends on your size, age, activity and job. Start by estimating your maintenance calories, then eat 500-750 fewer each day. For many adults that means losing a stone in roughly 9-14 weeks. Track your weekly average weight and adjust if nothing changes for 2-3 weeks.

Is losing 1kg a week realistic?

For people with more weight to lose, 1kg a week can be realistic in the early weeks. For people who are already fairly lean, 0.5kg a week is more sustainable. The NHS suggests 0.5-1kg a week as a safe range. If you lose much faster for long periods, you are more likely to lose muscle.

Why am I losing weight slower than expected?

The usual reasons are underestimating portions, weekend eating, fewer daily steps than you think and normal water changes from salt, stress, sleep or your menstrual cycle. Look at 2-3 weeks of average weight before changing anything. If you have been consistent and nothing is moving, speak to your GP to rule out medical causes.

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