Weight goal timeline calculator
Enter your weight now, a goal and a weekly pace you choose. The calculator draws the straight-line scenario: how many weeks it takes, the date it lands on and where you would be every four weeks.
Updated
A straight-line scenario from the pace you enter, not a prediction. Real weight change is rarely linear, and this page does not estimate what any medication or diet will do.
The formula this calculator uses
Fixed amount a week
weeks = |weight now − goal| ÷ weekly pace.
Percentage a week
weeks = ln(goal ÷ now) ÷ ln(1 − pace ÷ 100) when losing, ln(1 + pace ÷ 100) when gaining.
Dates and months
goal date = start date (today if empty) + round(weeks × 7) days · months = weeks ÷ 4.345.
Milestones
every 4 weeks up to 12 rows: fixed: now ∓ pace × week · percentage: now × (1 ∓ pace ÷ 100)^week.
Worked examples
Each row was entered into this calculator and the result copied as shown.
| Entry | Weeks | Goal date | About | Total change |
|---|---|---|---|---|
| 90 → 80 kg · 0.5 kg a week · from 20 Oct 2026 | 20 | Mar 9, 2027 | 4.6 months | 10 kg to lose |
| 90 → 80 kg · 0.5% a week · from 20 Oct 2026 | 23.5 | Apr 2, 2027 | 5.4 months | 10 kg to lose |
| 200 → 190 lb · 1 lb a week · from 1 Nov 2026 | 10 | Jan 10, 2027 | 2.3 months | 10 lb to lose |
What this calculator does not do
- It does not predict how much weight you will lose with Ozempic®, Mounjaro® or any other medication.
- It does not suggest a pace, a goal weight or a diet.
- It does not model plateaus, water changes or a pace that changes over time.
- It does not warn about fast or slow paces; it only flags a timeline longer than ten years as a likely typo.
About this estimate and your privacy
The result is what would happen if the pace you typed held exactly. Treat it as a scenario to compare your real weigh-ins against, not a schedule.
Everything is worked out by a script inside this page. The script makes no network requests, the page’s security policy (Content-Security-Policy with default-src none and no connect-src) would block them anyway, and nothing you type is stored, not even in your browser’s storage. Reload the page and the fields are empty again.
Next to each source below is what it supports on this page.
Ozempic® is a trademark of Novo Nordisk A/S. Mounjaro® is a trademark of Eli Lilly and Company. PepLabo is not affiliated with or endorsed by them.
Questions
Can this tell me how much I will lose on Ozempic® or Mounjaro®?
No. The calculator only uses the pace you type in. Results with any medication differ from person to person; your prescriber is the one to talk to about what to expect.
What pace does the CDC describe as gradual?
About 1 to 2 pounds (roughly 0.45 to 0.9 kg) a week. The CDC says people who lose weight at that gradual, steady pace are more likely to keep it off [1].
What is the difference between the two pace options?
A fixed pace takes the same amount off every week, so the line is straight. A percentage pace takes a share of your current weight, so each week’s amount shrinks a little as weight falls and the timeline is longer.
Why is real progress not a straight line?
This page cannot know: it only models the pace you enter. Compare the scenario with your actual weigh-ins and discuss differences with your clinician.
Do I need to enter a start date?
No. Leave it empty and the calculator starts from today in your browser’s time zone.
What do the four-weekly rows show?
The weight the scenario reaches every four weeks, up to twelve rows, and then the goal date itself.
Does it work for gaining weight?
Yes. If the goal is above your weight now, the same arithmetic runs the other way and the total shows "to gain".
Why does it warn about ten years?
A timeline that long is usually a typo, such as a pace entered in grams instead of kilograms. The calculator still shows the result.
Can I compare my real weigh-ins with this?
Yes. Log your weigh-ins in PepLabo and set your goal weight; the weight chart shows your actual line with the goal as a dashed line.
Sources
Sources checked on
- CDC. Steps for losing weight Supports: about 1 to 2 lb a week as gradual and steady; people losing at that pace more likely to keep it off.
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