How Much Weight Can You Lose in a Month? The Usual Range by Starting Weight

In a month, the usual range is about 2 to 4 kg (4 to 9 lb). That is four weeks at 0.5 to 1 kg (1 to 2 lb) a week. The CDC calls 1 to 2 lb a week gradual and steady. The range is for adults who have a reason to lose weight, and it sets neither a target nor a date. How much weight you can lose in a month depends on where you start.

How much weight can you lose in a month at your starting weight?

Take a 70 kg (154 lb) adult. At 0.5% to 1% of body weight a week, that’s 1.4 to 2.8 kg (3.1 to 6.2 lb) in four weeks. Heavier adults cover more kilograms in the same four weeks and lighter adults fewer, because the same percentage is taken from a different base.

The NHS and CDC give fixed amounts, but 1 kg is a bigger share of a 55 kg body than of a 120 kg one. So I add a ceiling of 1% of body weight a week. I borrowed the number from a review of contest preparation, where 0.5% to 1% a week was advised to protect muscle in lean athletes. For ordinary dieters it is my cautious choice and no clinical limit. In Hall’s dynamic model, adults with more body fat also lose more for the same change in intake, which fits the pattern below.

Each cell is the starting weight times the weekly percentage, times four weeks, rounded to 0.1 kg.

Starting weight	0.5% a week	0.75% a week	1% a week
55 kg (121 lb)	1.1 kg (2.4 lb)	1.7 kg (3.6 lb)	2.2 kg (4.9 lb)
70 kg (154 lb)	1.4 kg (3.1 lb)	2.1 kg (4.6 lb)	2.8 kg (6.2 lb)
85 kg (187 lb)	1.7 kg (3.7 lb)	2.6 kg (5.6 lb)	3.4 kg (7.5 lb)
100 kg (220 lb)	2.0 kg (4.4 lb)	3.0 kg (6.6 lb)	4.0 kg (8.8 lb)
120 kg (265 lb)	2.4 kg (5.3 lb)	3.6 kg (7.9 lb)	4.0 kg (8.8 lb), capped at 1 kg a week

Read across a row for the pace and down a column for the starting weight. A 55 kg adult at 1% a week reaches 2.2 kg. The low end of the NHS range gives 2.0 kg over four weeks, so the two nearly coincide. At 100 kg the 1% ceiling and the NHS ceiling meet at 4.0 kg, because 1% of 100 kg is exactly 1 kg a week. Above that, 1% would pass 1 kg a week, so the NHS figure binds first. The 120 kg row shows it. 1% would give 4.8 kg, and the cap holds it at 4.0.

Two notes on units. A calendar month averages 4.3 weeks, so multiply the table by about 1.09 for a full month. UK readers may think in stone, and the top of the table, 8.8 lb, is under one stone (14 lb). How to lose a stone in a month works through that case in weeks.

What daily calorie gap does each pace need?

About 1,100 kcal a day for each 1 kg of weekly loss. The old rule treats 1 kg of body weight as 7,700 kcal, and 7,700 divided by 7 days is 1,100. A calorie deficit is that daily gap between what you eat and what your body uses.

A big gap hits a hard stop. The AHA/ACC/TOS guideline lists usual intakes in weight-loss programs of 1,200 to 1,500 kcal a day for women and 1,500 to 1,800 for men. I treat the low end of each as a floor and never plan under it, so the usable gap depends on your maintenance. The last two columns give the lowest maintenance intake that leaves room for the 1% gap.

Starting weight	Daily gap at 0.5%	Daily gap at 1%	Lowest maintenance for a woman (floor 1,200 kcal)	Lowest maintenance for a man (floor 1,500 kcal)
55 kg	303 kcal	605 kcal	1,805 kcal	2,105 kcal
70 kg	385 kcal	770 kcal	1,970 kcal	2,270 kcal
85 kg	468 kcal	935 kcal	2,135 kcal	2,435 kcal
100 kg	550 kcal	1,100 kcal	2,300 kcal	2,600 kcal
120 kg	660 kcal	1,100 kcal (capped)	2,300 kcal	2,600 kcal

Maintenance means the calories at which your weight holds across weeks. If yours is lower than the figure in your row, the 1% pace is closed to you and a slower one is the answer. Outside the capped row, the 0.5% column is half of the 1% gap.

The calorie calculator does these sums for one person from age, height, weight and activity. It applies the limits used here: 1% of body weight a week at most, and never under 1,200 calories for women or 1,500 for men.

Why does the first month often show more on the scale?

Early loss isn’t all fat. In the first days and weeks the body also gives up glycogen and the water stored with it, plus some protein. Thomas and colleagues describe two phases: a rapid one that lasts days or weeks, then a slower one that runs for months. In the CALERIE I study, the measured energy content of weight change at week 4 was 4,858 kcal per kg. By week 24 it had risen to 6,569. Both sit below 7,700, which fits an early loss that is richer in water and lower in fat.

Those are means for participants put on a diet 25% below their energy needs or on a very-low-calorie one of 890 kcal a day. Intake was closely monitored. An everyday diet may land elsewhere.

Glycogen is the form in which the body stores carbohydrate. A review for coaches puts whole-body stores at about 600 g, a figure that varies widely. Each gram carries at least 3 g of water. Kreitzman and colleagues give three to four parts water for glycogen. They measured potassium shifts in 11 people after 4 days on a very-low-calorie diet. Here is my arithmetic: 600 g of glycogen plus three to four times that in water comes to 2.4 to 3.0 kg. It is a ceiling for a full store. The real drop can be smaller.

To see what this does to a month, I divided the same daily gap by 7,700 and by the week-4 value. That applies a week-4 figure to all four weeks, so read the last column as an illustration.

Daily gap	Gap over 28 days	Scale change by the 7,700 rule	Scale change at 4,858 kcal per kg
250 kcal	7,000 kcal	0.9 kg (2.0 lb)	1.4 kg (3.2 lb)
500 kcal	14,000 kcal	1.8 kg (4.0 lb)	2.9 kg (6.4 lb)
750 kcal	21,000 kcal	2.7 kg (6.0 lb)	4.3 kg (9.5 lb)

The 750 row passes the NHS ceiling on the scale. By the 7,700 rule that gap is 0.7 kg a week, inside the range, yet the scale shows 4.3 kg (9.5 lb). Part of the difference is water and glycogen. None of it means you’re losing fat faster than the range.

Thomas and colleagues tie the slowdown that follows to two things: the glycogen pool running out and the body adapting. So a weigh-in on day 8 and another on day 28 can show two different speeds from one unchanged habit. Nothing is broken.

The 7,700 rule works as a first guess and fails as a forecast. Over a year it overstates loss, because a lighter body uses less energy, and why 3,500 kcal per pound misleads walks through that. In one month the error runs the other way, as the table shows. Hall gives 39.5 MJ per kg of body fat and 7.6 MJ per kg of lean mass. By my conversion that is about 9,400 and 1,800 kcal. The 7,700 figure falls between the two, as a blend of fat and lean tissue would. That is my reading, not Hall’s wording, and one blend can’t fit both week 1 and week 24.

How do I check my own month?

Start with how wrong your plan can be. Hall notes that a free-living person’s energy needs can’t be measured to better than about 5%. The error is usually larger unless doubly labeled water is used. Say you guess your maintenance at 2,400 kcal and eat 1,900, a 500 kcal gap. If your true maintenance is 5% lower, at 2,280, the real gap is 380 kcal. Over 28 days that’s 10,640 kcal instead of 14,000. By the 7,700 rule it comes to 1.4 kg instead of 1.8 kg, a difference of 0.4 kg. Small, but it’s enough to read as a miss.

A month that lands at 1.4 kg when you planned 1.8 kg sits inside the noise of the estimate. That isn’t failure. The fix is a second look at the numbers after two weeks of averaged weigh-ins, not a bigger cut.

Single readings mislead too. In a pan-European weight-loss maintenance trial, weekly fluctuations averaged about 0.35%, with weight highest on Monday and lowest on Friday. At 70 kg, 0.35% is about 0.25 kg, less than a tenth of the 2.8 kg a 1% pace gives in four weeks.

Today, write down your starting weight and the date. Find the closest row in the first table and take the pace from the 0.5% column rather than the 1% one. Check whether your maintenance clears the figure in the second table. After that, weigh yourself three mornings a week, after the bathroom and before food. Same scale, same clothes. Average each week, then compare week 1 with week 4. If the average stalls for three weeks, why you may not be losing weight in a calorie deficit goes through the checks in order.

Is 10 pounds in a month realistic?

Not inside the usual range. Ten pounds in four weeks is 2.5 lb a week. The NHS range tops out at 2 lb. Four weeks at the top gives 8 lb, or 4 kg (8.8 lb) if you count in kilograms. For 10 lb to sit within 1% of body weight a week, you would need to weigh at least 250 lb (113 kg). Even then the weekly figure would pass the NHS ceiling.

A scale can still show close to 10 lb after four weeks once early water is in the mix. My closest row is the 750 kcal one, at 9.5 lb on the scale. I wouldn’t plan around it. Part of that figure is glycogen and water, and it’s no pace to chase.

How long does 10 lb take, then? At 1 to 2 lb a week it takes 5 to 10 weeks. That’s 10 divided by 2 and 10 divided by 1: arithmetic, no forecast. Real weight bends and stalls.

One trial compared a slower and a faster pace. Garthe and colleagues randomized 24 elite athletes, who lifted four times a week. The plan was a loss of 0.7% or 1.4% of body weight a week. They reached 0.7% and 1.0%. Both groups lost about 5.5% of their weight, the slower one in 8.5 weeks and the faster in 5.3. The slower group lost 31% of its fat mass and gained 2.1% lean mass. The faster group lost 21% of its fat mass, and its lean mass stayed unchanged. It’s a small trial. The athletes were young and trained, so I read it as a reason to go slower. It doesn’t prove anything for everyone. If a faster pace tempts you, a calorie deficit for 2 pounds a week shows which body weights it fits and which it doesn’t.

The pace usually slows after month one. The AHA/ACC/TOS guideline sets an initial goal of 5% to 10% of baseline weight within 6 months, for the adults it covers. Take an 80 kg adult: 4 to 8 kg over about 26 weeks. That averages 0.6 to 1.2 kg per four weeks. The first-month range of 2 to 4 kg is higher than that average, which fits a pace that slows.

When is this range the wrong thing to read?

It doesn’t apply if you’re under 18, pregnant or breastfeeding, or living with a medical condition or medicine that changes your weight. A clinician sets the pace in those cases and no table does. It also doesn’t apply if your weight already sits inside the usual range for your height. There’s no gap to close, and holding steady is a complete plan. Unplanned weight loss is a reason to see a doctor.

If counting calories has started to feel hard to stop, or eating feels out of control, talk to someone: ANAD in the US (1-888-375-7767), Beat in England (0808 801 0677), NEDIC in Canada (1-866-633-4220) or the Butterfly Foundation in Australia (1800 33 4673). If you’re in danger right now, call your local emergency number. Other UK numbers and crisis lines are on our crisis support page.

A month is a short, noisy window. Pick the lower pace for your starting weight and keep your intake above the floor. At the end, ask one question: did the average move the way your row allows? Four weeks can’t answer more than that.