For most adults, a deficit of 250–500 calories a day below maintenance is the right size. 500 suits most people starting out and gives roughly 0.45 kg (1 lb) of loss a week at first. 250 suits people who are already lean, smaller, or want to protect their training. Don't let your target fall below about 1,200 calories a day for women or 1,500 for men without medical supervision. The cutting calorie calculator sets both deficits for you and flags low targets, and the TDEE calculator shows every goal.
250 vs 500 calories
| 250 cal/day | 500 cal/day | |
|---|---|---|
| Rough loss per week at first | About 0.23 kg (0.5 lb) | About 0.45 kg (1 lb) |
| Hunger and energy | Easier | Noticeable, but manageable for most people |
| Muscle retention | Easier to protect | Needs good protein and training |
| Best for | Lean or smaller people, athletes in season | Most people starting a diet |
These rates use the rule of thumb that about 7,700 calories equals 1 kg of body weight. Over months it overstates loss, because your body burns less as you get smaller, as researchers at the US National Institutes of Health showed in 2011.
Worked examples
The 1,200 and 1,500 floors
These figures are commonly cited minimums for dieting without medical supervision: about 1,200 calories a day for women and 1,500 for men. They are not magic numbers, but below them it gets hard to eat enough protein, fibre, vitamins and minerals, and hunger tends to win. The calculators on this site flag any target below them.
Picking a pace you can keep
The best deficit is the one you can hold for months, not days. The US Centers for Disease Control and Prevention note that people who lose about 1–2 lb (0.5–1 kg) a week gradually and steadily are more successful at keeping weight off. If a 500 deficit leaves you exhausted, hungry all day or skipping training, move to 250. Slower progress you can sustain beats a fast start you abandon.
Who should not diet without supervision
- Anyone pregnant or breastfeeding
- Anyone under 18
- Anyone with a current or past eating disorder
- People taking medication that affects blood sugar, such as insulin
- People with kidney, heart or other chronic conditions
- Older adults who have lost weight without trying or feel frail
If any of these apply, speak to a doctor or registered dietitian before cutting calories.
Adjusting as you go
After 2–3 weeks, compare weekly average weights. Losing faster than about 1% of body weight a week? Add 100–200 calories. Not losing at all? Check your tracking, then cut 100–150. Recalculate after every 4–5 kg lost. How to track and adjust your calories week by week has the full routine.
Set your deficit, with a safety check built in.
Open the cutting calculatorFrequently asked questions
Is a 500 calorie deficit too much?
Can I eat less than 1,200 calories a day?
How fast should I lose weight?
Should my deficit change over time?
Keep reading
Sources
- Hall KD, Sacks G, Chandramohan D, et al. Quantification of the effect of energy imbalance on bodyweight. Lancet. 2011;378(9793):826–837. PubMed 21872751
- National Institute of Diabetes and Digestive and Kidney Diseases. Body Weight Planner. niddk.nih.gov
- Centers for Disease Control and Prevention. Losing Weight: gradual, steady weight loss of about 1 to 2 pounds per week. cdc.gov.
- Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241–247. PubMed 2305711