Felix, 6 kg to lose
76 kg to 70 kg, 500 kcal
About 13 weeks if the gap holds. Real weeks wobble.
Calorie Deficit Calculator
Estimate how many weeks a chosen daily calorie deficit may take to reach a weight goal in stone or kilograms.
Your details
Pick the units you use day to day, then calculate for a clear UK friendly result.
What is this calculator?
Estimate how many weeks a chosen daily calorie deficit may take to reach a weight goal in stone or kilograms.
How it works
- Enter current weight, goal weight and a daily deficit in kcal.
- We convert the weight gap to an energy estimate.
- We then divide by your daily deficit for a week range.
Common questions
What is the calorie deficit?
It turns the numbers you type into a calorie deficit figure you can read in one sitting. Use it as a guide, not a diagnosis.
Is 500 kcal a day a good deficit?
It is a common adult starting point for gradual loss. Smaller can be easier if hunger spikes.
Why did my weight stall?
Water, muscle gain, under-counted food and adaptation all feature. Recheck habits before cutting harder.
Should I go below my BMR?
Usually no for a self directed plan. Aim below maintenance, not below true resting needs, without professional advice.
Example scenarios
Ceri, slower cut
82 kg to 76 kg, 300 kcal
About 22 weeks. Easier to keep.
Hassan, smaller gap
70 kg to 67 kg, 400 kcal
About 8 weeks.
Understanding your results
Weeks assume about 7,700 kcal per kilogram and a steady daily gap. Real weeks wobble. A later date you can keep beats a crash.
About this result
Guidance only. Calculations run in your browser. Numbers are estimates, not a diagnosis.
How we calculate
About 7,700 kcal per kg of body fat as a rule of thumb, divided by daily deficit.
Sources
Limitations
- Real loss is rarely linear.
- Very large deficits are hard to sustain and can be unsafe.
- Muscle, water and hormones affect the scales.
When to seek help
See your GP or a dietitian before a large calorie cut, or if you have a history of disordered eating.
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