When to Recalculate TDEE While Losing Weight

On this page

1. The rule of thumb
2. Why every 4 to 5 kg?
3. How to recalculate, step by step
4. How your calories change as you lose
5. The better method: recalculate from your own data
6. Two worked recalculations
7. When the two methods disagree
8. If you use the app
9. After a three-week stall
10. After a diet break
11. When the new target reaches your floor
12. Common mistakes
13. Questions about recalculating TDEE

The rule of thumb

Recalculate when either of these happens:

• You have lost 4 to 5 kg (about 10 lb) since you last set your target.
• Your weekly average weight has been flat for three weeks while you have been logging accurately and eating your target.

Also recalculate if your routine changes in a way that affects activity: a new job, a move to working from home, an injury, a new training plan.

Why every 4 to 5 kg?

Because that is roughly where the change becomes big enough to matter. Each kilo lost takes about 10 kcal off your resting burn, and 12 to 19 kcal off your TDEE depending on your activity factor. So 5 kg is worth about 60 to 95 kcal a day. Below that, the change is smaller than normal day-to-day variation and the error in the estimate itself. Recalculating after every half kilo just chases noise.

How to recalculate, step by step

1. Use your weekly average weight. Average your last seven morning weigh-ins. Don’t use your lowest day, which is usually a low-water day.
2. Re-check your activity level. Many people move less as they diet. If your steps or training have dropped, choose the level that fits now.
3. Recalculate your TDEE with the TDEE calculator.
4. Reapply your deficit as a percentage. If you were eating 20% below TDEE, take 20% off the new number.
5. Check the limits: above about 1,200 kcal (women) or 1,500 kcal (men) a day, and a pace under about 1% of your body weight a week.
6. Test it for two to three weeks before changing anything else.

How your calories change as you lose

A 45-year-old man, 178 cm (5′10″), lightly active, starting at 105 kg (231 lb) with a 20% deficit:

Recalculating keeps his deficit near 500 kcal and his loss near 0.45 kg (1 lb) a week. Without recalculating, his deficit halves by the time he reaches 85 kg, and he loses about half as fast. He only needs to cut about 55 kcal a day at each step, the equivalent of one small piece of fruit, which is why regular small updates are easier than one big cut later.

The better method: recalculate from your own data

A formula assumes you are average. Your own log doesn’t. If you have been logging food and weighing yourself for three or four weeks, work out your real TDEE:

Real TDEE = average calories eaten − (weight change in kg × 7,700 ÷ days)

Then set your new target from that. The adaptive TDEE calculator does it for you, and the TDEE Calculator app updates it continuously. A measured TDEE automatically includes any drop in your daily movement and any adaptation, which a formula can’t see.

Two worked recalculations

With the formula. A 33-year-old woman, 163 cm (5′4″), lightly active, started at 78 kg (172 lb) with a TDEE of about 2,025 kcal and a 20% deficit target of 1,620 kcal. Eight weeks later her weekly average is 73 kg (161 lb). Her new TDEE is about 1,956 kcal, so her new target is about 1,565 kcal: 55 kcal less, roughly a slice of bread fewer every other day.

From her own data. Over the last four weeks she ate an average of 1,690 kcal (a little above plan, as it turns out) and her weekly average fell by 1.4 kg. That is 1.4 × 7,700 ÷ 28 = 385 kcal a day from storage, so her measured TDEE is about 2,075 kcal. That is a little higher than the formula’s 1,956, probably because she walks more than the average lightly active person. Using the measured figure, a 20% deficit is about 1,660 kcal, so she can keep eating close to what she has been eating and still lose at the same pace.

When the two methods disagree

If your measured TDEE is lower than the formula, trust the measurement, as long as your log has been complete and the window didn’t start in the first week of the diet. A gap of 100 to 200 kcal is common. If the measured number is much lower, say 400 kcal or more, check your logging and steps before accepting it. If it is higher, you probably move more than the average person at your activity level. Use it, and enjoy eating a little more.

If you use the app

The TDEE Calculator app measures your TDEE from your food and weight log over the last four weeks and updates your target as it changes, so there is no separate recalculation step. It is still worth checking your activity level and goal now and then, especially if your routine changes.

After a three-week stall

A stall of three weeks with accurate logging usually means your deficit has shrunk to nothing. Recalculate as above, check your steps, and if you have been dieting for months and feel worn out, consider a week or two at maintenance first. Our plateau guide has the full checklist.

After a diet break

When you return from a week or two at maintenance, recalculate from your current weekly average. The scale may be a kilo or so higher than before the break because of water and glycogen. Use the new average anyway; the extra water drops off again within a week or two of dieting.

When the new target reaches your floor

As you get lighter, a percentage deficit eventually lands near 1,200 kcal (women) or 1,500 kcal (men). Don’t go lower without medical supervision. Instead:

• accept a slower pace, such as 0.25 kg (½ lb) a week;
• raise your TDEE with more daily steps or another training session;
• consider whether you are close enough to your goal to switch to maintenance.

Common mistakes

• Using your lowest weigh-in instead of a weekly average.
• Recalculating every week, which chases water rather than fat.
• Keeping the same fixed deficit in calories instead of a percentage, so the cut gets relatively harder as you shrink.
• Raising your activity level to eat more without actually moving more.
• Making several changes at once, so you can’t tell which one worked.

Questions about recalculating TDEE

How often should I recalculate my TDEE when losing weight?

After every 4 to 5 kg (10 lb) lost, or after a three-week stall with accurate logging. Weekly recalculation isn’t useful because water changes are bigger than the real change in TDEE.

Should I use my lowest weight when recalculating?

No. Use the average of your last seven morning weigh-ins. Your lowest weight is usually a low-water day and would make your new target too low.

How much should my calories go down after losing 5 kg?

Usually by about 50 to 75 kcal a day if you keep the same percentage deficit, or 60 to 95 kcal of TDEE. It is a small change, which is why regular updates are easy.

Should I recalculate after a diet break?

Yes. Use your current weekly average, even if it is slightly higher from water after the break, and reapply your deficit.

What if my recalculated target is below 1,200 calories?

Don’t go below about 1,200 kcal (women) or 1,500 kcal (men) without medical supervision. Slow your pace, add daily steps or consider switching to maintenance.

Do my macros change when I recalculate?

A little. Protein is set from your body weight, so it falls slightly as you get lighter. Carbs and fat fill the remaining calories, so they shrink with the new target.

Should my activity level change as I lose weight?

Only if your actual movement changes. Losing weight doesn’t change your level by itself, but many people walk less while dieting, so check your steps when you recalculate.

What if I’m losing faster than planned?

After the first two weeks, losing more than about 1% of your body weight a week is faster than most people need. Add 100 to 200 kcal a day and check again after two weeks, especially if you feel tired or your training is suffering.

Can I just take 50 calories off every 5 kg?

As a shortcut, roughly yes: that is about what a full recalculation gives most people. A proper recalculation also catches changes in your activity, which can matter more.

Is it better to recalculate with a formula or from my log?

From your log, if you have three or four weeks of complete data. A measured TDEE includes changes in your movement and any adaptation; a formula only knows your new weight.

Sources

1. Hall KD, Sacks G, Chandramohan D, et al. Quantification of the effect of energy imbalance on bodyweight. Lancet. 2011;378(9793):826-837. doi.org/10.1016/S0140-6736(11)60812-X
2. Thomas DM, Martin CK, Lettieri S, et al. Can a weight loss of one pound a week be achieved with a 3500-kcal deficit? Commentary on a commonly accepted rule. Int J Obes (Lond). 2013;37(12):1611-1613. doi.org/10.1038/ijo.2013.51
3. Mifflin MD, St Jeor ST, Hill LA, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241-247. doi.org/10.1093/ajcn/51.2.241
4. Rosenbaum M, Leibel RL. Adaptive thermogenesis in humans. Int J Obes (Lond). 2010;34(Suppl 1):S47-S55. doi.org/10.1038/ijo.2010.184
5. Byrne NM, Sainsbury A, King NA, Hills AP, Wood RE. Intermittent energy restriction improves weight loss efficiency in obese men: the MATADOR study. Int J Obes (Lond). 2018;42(2):129-138. doi.org/10.1038/ijo.2017.206