Goal Weight Date Calculator: When Will I Reach My Goal Weight?
The calendar date you would reach a goal weight, losing or gaining, from a fixed weekly rate, a percentage of body weight per week, or a daily calorie deficit with metabolic slowdown, plus a week-by-week milestone table and weight chart.
How it works
Weekly amount: weeks = |current − goal| ÷ rate · % per week: weeks = ln(goal ÷ current) ÷ ln(1 ∓ p) · Calorie deficit D: days = |Δ| × 3,500 ÷ D, or with metabolic slowdown days = −350 × ln(1 − 10 |Δ| ÷ D) · Goal date = start date + days
The calculator counts forward from today (or a start date you choose) by the time it takes to cover the gap between your current and goal weight. You can plan three ways. A fixed weekly amount, such as 1 lb (0.45 kg) a week, gives a straight line. A percentage of body weight per week, the way many coaches set targets, takes off a little less each week as you get lighter, so the date is later. A daily calorie deficit (or surplus to gain) uses the energy of body tissue, about 3,500 kcal per pound (7,700 kcal per kg); with the slowdown option on, it also accounts for the fact that a lighter body needs about 10 kcal less per day for each pound lost, the rule of thumb from the NIH Body Weight Planner research by Kevin Hall. That makes a fixed deficit level off: a 500 kcal/day cut eventually removes about 50 lb, half of it in roughly eight months. The results show the goal date, weeks and months, the average and first-week change, the calorie gap the plan implies and a milestone table. Guidelines usually call 1–2 lb (0.5–1 kg) or 0.5–1% of body weight a week sustainable for loss. Water, salt and food in the gut move the scale by a few pounds from day to day, so track a weekly average.
Worked example
Default: 190 lb now, a 170 lb goal and 1 lb a week, starting 24 October 2026. The gap is 20 lb (10.5% of body weight), so 20 ÷ 1 = 20 weeks or 140 days, about 4.6 months, giving 13 March 2027. One pound a week implies a deficit of about 500 kcal/day (3,500 ÷ 7). At 0.5% of body weight a week instead, weeks = ln(170 ÷ 190) ÷ ln(0.995) = 22.2, about 155 days. With a 500 kcal/day deficit and the slowdown model, the eventual change is 500 ÷ 10 = 50 lb, and days = −350 × ln(1 − 20 ÷ 50) = 179, about 25.5 weeks.
Sources: NIDDK: Body Weight Planner · CDC: Losing weight
Frequently asked questions
Why might I reach my goal later than the date shown?
Weight loss slows as you get lighter because a smaller body burns fewer calories, and plateaus, water shifts, holidays and illness add delays. Use the % per week or calorie-deficit plan with the slowdown on for a more realistic date, and allow a buffer.
What weekly rate should I choose?
For weight loss, 0.5–1% of body weight a week, about 1–2 lb (0.5–1 kg) for many adults, is the usual sustainable range. Faster rates cost more muscle and are harder to maintain. For weight gain, about 0.25–0.5 lb (0.1–0.25 kg) a week limits fat gain.
How many calories a day do I need to cut to lose 1 lb a week?
About 500 kcal a day, using the 3,500 kcal-per-pound rule (1,100 kcal a day for 1 kg a week). Because energy needs fall as you lose weight, the same deficit gives slower loss over time, so recheck your intake every few weeks.
Is the 3,500-calorie rule accurate?
It is a fair estimate for the first weeks but overestimates long-term loss, because it ignores metabolic adaptation. Research by Kevin Hall at the NIH suggests each 10 kcal/day of sustained change eventually changes weight by about 1 lb, with half of it reached in about a year; the slowdown option uses that rule.
Does this work for weight gain too?
Yes. If the goal is above your current weight the calculator counts the gap the same way and projects the date at your chosen weekly amount, percentage or calorie surplus.
Related calculators
This is a general educational estimate, not medical or dietary advice. Weight, body composition and energy needs respond differently for everyone; for a plan tailored to you, talk to a doctor or registered dietitian, especially before very-low-calorie diets or if you have a medical condition.