Weight Loss Timeline
Multiply the kilos to lose by 7,700 kcal and divide by the daily deficit. Losing 10 kg at 500 kcal a day takes about 22 weeks.
Your numbers
Time needed
22wk
Difference
10kg
Result
5.1mo
Formula
Time needed = (Weight (kg) − Target weight) × 7700 ÷ (Daily deficit × 7)
BMR falls as you lose weight, so the later weeks run slower than the maths suggests — allow extra time.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| Weight (kg)The second weight you are comparing against. | 80 | 10 ~ 300 |
| Target weight (kg)The weight that lands you on the target BMI. | 70 | 10 ~ 300 |
| Daily deficit (kcal)How many more calories you burn than you eat each day. | 500 | 100 ~ 1,500 |
Step by step
Quick reference table
Results when only Weight (kg) changes and everything else stays put.
| Weight (kg) | Time needed (wk) | Difference (kg) | Result (mo) |
|---|---|---|---|
| 40 | 0 | 0 | 0 |
| 60 | 0 | 0 | 0 |
| 80 | 22 | 10 | 5.1 |
| 120 | 110 | 50 | 25.3 |
| 160 | 198 | 90 | 45.6 |
What each result means
| Result | At default values |
|---|---|
| Time needed (wk)Weeks to the goal if you keep this pace. | 22 |
| Difference (kg)The gap between two values — a quantity, not a rate. | 10 |
| Result (mo)What the formula gives back — the answer this page is for. | 5.1 |
Common mistakes
BMR falls as you lose weight, so the later weeks run slower than the maths suggests — allow extra time.
Glossary
- Weight (kg)
- The second weight you are comparing against.
- Target weight
- The weight that lands you on the target BMI.
- Daily deficit
- How many more calories you burn than you eat each day.
- Time needed
- Weeks to the goal if you keep this pace.
- Difference
- The gap between two values — a quantity, not a rate.
- Result
- What the formula gives back — the answer this page is for.
Frequently asked questions
Q. How is Weight Loss Timeline calculated?
Time needed = (Weight (kg) − Target weight) × 7700 ÷ (Daily deficit × 7) — Multiply the kilos to lose by 7,700 kcal and divide by the daily deficit. Losing 10 kg at 500 kcal a day takes about 22 weeks.
Q. Can you walk through an example?
With Weight (kg) 80, Target weight 70kg, Daily deficit 500kcal, the answer is Time needed 22wk.
Q. What do I need to enter?
Enter Weight (kg), Target weight, Daily deficit. The result recalculates as you type, and an empty box counts as zero.
Q. How much does the answer move if I change a number?
Changing only Weight (kg) moves the answer to Weight (kg) 40 → Time needed (wk) 0 and Weight (kg) 160 → Time needed (wk) 198. The table below lays out five steps.
Q. How are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
Q. Anything to watch out for?
BMR falls as you lose weight, so the later weeks run slower than the maths suggests — allow extra time.
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