Weight loss timeline calculator: project weekly weight change and goal date from current weight, deficit, and activity. Editable rates, free, runs locally.
Updates automatically as you type.
Calculated in your browser; your inputs are not sent to us. Privacy
Results will appear here.
General estimate for planning only — not medical advice. Consult a doctor about your specific situation.
Calculation details
Every figure above is calculated locally in your browser from the assumptions shown. No inputs are sent anywhere. See the methodology section below for the formulas used.
Use this resultShare the current inputs, or ask ChatGPT to explain the calculation in context.
Ask an AI to explain this result
Share this result
Review the generated output before relying on it.
This tool runs in your browser. Your calculator inputs and results are never transmitted to us or to ad/affiliate partners. Ads and sponsored links may set third-party cookies to serve and measure them, but they never receive your calculation values. If you explicitly save a scenario, its permitted fields stay in local browser storage until you clear them. See our Privacy Policy.
Use this result
Share the current inputs or ask ChatGPT to explain the calculation in context.
No unrelated authority link is added merely to make this page look sourced. Tool-specific external sources are shown only when they directly support the method, rate, or rule.
Assumptions to Verify
These tools provide general estimates for planning and education only.
They are not medical advice and not a substitute for a qualified healthcare professional.
Always consult your doctor or another healthcare provider about your specific situation.
Privacy: The calculation runs in this browser. Shared links contain the page address only, not your inputs or results.
A Worked Example You Can Check by Hand
Say you weigh 190 lb, your goal is 160 lb, and you plan to lose 1.5 lb per week. The total drop is 190 minus 160, which is 30 lb. Divide 30 by 1.5 and you get 20 weeks. That is the entire calculation: weeks = (current - goal) / weekly rate.
The tool then converts 20 weeks into a calendar date. Twenty weeks is 140 days (20 x 7), so it adds 140 days to today. If you start on January 5, the math lands around May 26. Note the date is an approximation: real weight loss is not a straight line, so treat it as a midpoint estimate, not a deadline.
Compare a second rate on the same 30 lb goal. At 2 lb per week it takes 15 weeks; at 0.5 lb per week it takes 60 weeks, roughly 14 months. The input has the largest effect of anything on the page, which is why the 1 to 2 lb per week range is highlighted: anything faster usually requires a deficit most people cannot hold, and anything slower risks losing momentum before you get there.
What the Straight-Line Math Gets Wrong
The formula assumes you lose the same amount every week, and bodies do not work that way. Week 1 often drops 3 to 5 lb because cutting carbs lowers water and glycogen stores; the whoosh of early progress can vanish by week 3 even with the same effort. Conversely, plateaus of 2 to 4 weeks are normal, so a 20-week projection realistically lands closer to weeks 22 to 26.
The rate you enter is not guaranteed to be the rate you experience. A 1.5 lb per week pace needs a deficit of roughly 750 calories per day (1 lb of fat is about 3,500 calories). For a 160 lb woman eating 1,800 calories to maintain, that means a 1,050 calorie daily gap, which most people will not sustain. Her actual sustainable rate may be 0.75 lb per week, doubling the timeline to 40 weeks.
Two edge cases the tool flags but cannot fix: strength training and higher protein intake can add lean mass while cutting fat, so the scale may barely move even as your body changes, and if your goal is within 10 to 15 lb of your current weight, the last 5 lb typically moves at half the pace of the first 15. Add slack rather than expecting the printed date to hold.
