When will you actually reach your goal weight? Enter your current weight, your goal, and how fast you plan to lose, and this calculator gives you a realistic date — not a guess. At 1 lb per week, losing 30 lb takes 30 weeks, and the math behind that date is the 3,500-calorie rule: one pound of body fat stores roughly 3,500 calories, so a steady 500-calorie daily deficit adds up to about 1 lb a week. Our guide to how long it takes to reach your goal weight explains why the last few pounds are the slowest — and why a date that looks far away is usually the honest one.
Losing 30 lb at 1 lb a week takes 30 weeks — about 7 months. At 2 lb a week it takes 15 weeks, but that pace needs a 1,000-calorie daily deficit and is only realistic for people with a lot to lose. The calculator below also checks your pace against the commonly cited ceiling of 1% of bodyweight per week, and tells you the daily deficit your pace requires.
The calculator uses three steps, and all three are visible in your result. First, the pounds to lose: current weight minus goal weight. Second, the weeks it takes: pounds to lose divided by your weekly rate. Third, the date: your start date plus that many weeks. The calorie side comes from the 3,500-calorie rule — one pound of body fat stores roughly 3,500 calories, so losing 1 lb a week needs a deficit of 3,500 calories a week, or 500 a day; 2 lb a week needs 1,000 a day; half a pound a week needs 250 a day. Those are the numbers in the table below, and they are the same numbers your result shows.
| Weekly rate | Daily deficit needed | Weeks for 10 lb | Weeks for 20 lb | Weeks for 30 lb |
|---|---|---|---|---|
| 0.5 lb/week | 250 calories | 20 | 40 | 60 |
| 1 lb/week | 500 calories | 10 | 20 | 30 |
| 1.5 lb/week | 750 calories | ~7 | ~13 | 20 |
| 2 lb/week | 1,000 calories | 5 | 10 | 15 |
One honest caveat: the 3,500-calorie rule is an approximation, and it overstates speed slightly as you get lighter. Researcher Kevin Hall's dynamic models show the body adapts — a smaller body burns fewer calories, so the same deficit produces slower loss over time. That is why the calculator's date is a planning estimate, not a promise, and why the guide on how long it takes to reach your goal weight recommends rechecking your date every month against your real weigh-ins. The US Centers for Disease Control and Prevention (CDC) recommends losing 1 to 2 lb a week as a gradual, steady pace, and that range is exactly what this tool's rate menu offers.
The fastest safe pace is not the same for everyone — it scales with how much you weigh. A widely used coaching guideline caps fat loss at about 1% of bodyweight per week: for a 200 lb person that is 2 lb a week, for a 150 lb person it is 1.5 lb a week, and for a 180 lb person it is 1.8 lb a week. Faster than that, and a growing share of what you lose is muscle, not fat — and muscle is exactly what keeps your metabolism up while you diet. The calculator checks your chosen rate against your 1% ceiling and flags it if you picked faster. If it flags you, drop the rate a notch: the date moves a few weeks later, but the weight you lose is more likely to be fat, and far more likely to stay off. People with a BMI over 30 can often sustain the faster end of the range under medical supervision; people close to their goal weight should expect the slower end, because there is simply less fat to lose.
Example 1 — 200 lb to 170 lb at 1 lb a week. Pounds to lose: 200 − 170 = 30 lb. Weeks: 30 ÷ 1 = 30 weeks, or 210 days. Starting November 6, 2026, that lands on June 4, 2027. Daily deficit: 1 × 3,500 ÷ 7 = 500 calories a day. The 1% ceiling for 200 lb is 2 lb a week, so 1 lb a week is comfortably inside it.
Example 2 — 180 lb to 160 lb at 2 lb a week. Pounds to lose: 180 − 160 = 20 lb. Weeks: 20 ÷ 2 = 10 weeks, or 70 days. Starting November 6, 2026, that lands on January 15, 2027. Daily deficit: 2 × 3,500 ÷ 7 = 1,000 calories a day — a large deficit that needs both food cuts and extra activity, and a diet break is sensible if hunger or fatigue climbs. The 1% ceiling for 180 lb is 1.8 lb a week, so 2 lb a week is slightly above it and the calculator flags it.
Example 3 — 150 lb to 140 lb at 0.5 lb a week. Pounds to lose: 150 − 140 = 10 lb. Weeks: 10 ÷ 0.5 = 20 weeks, or 140 days. Starting November 6, 2026, that lands on March 26, 2027. Daily deficit: 0.5 × 3,500 ÷ 7 = 250 calories a day — about one snack, or a 30-minute brisk walk. The 1% ceiling for 150 lb is 1.5 lb a week, so 0.5 lb a week is well inside it, and it is the right pace for the last 10 lb, which always come off slowest.
Your date is a plan, not a deadline — use it to set the deficit and then manage the weeks. First, turn the daily deficit into a daily target with our calorie deficit calculator and weight loss calculator: the deficit tells you how much to cut, those tools tell you what to eat. Second, weigh yourself 2 to 3 times a week under the same conditions (morning, after the bathroom, before eating) and compare the weekly average to the plan — daily weight swings 2 to 4 lb with water, glycogen, and food, so the average is the only number that matters. Third, expect a plateau around week 6 to 8 and again near the end: your body is lighter, so it burns fewer calories, and a 500-calorie deficit slowly becomes a 350-calorie one. When the scale stalls for 3 weeks, recheck your maintenance calories with our maintenance calorie calculator and trim another 100 to 200 calories, or add a few thousand steps. Fourth, plan a diet break: research on intermittent energy restriction (the MATADOR trial, Byrne et al. 2017) found that two-week breaks at maintenance, taken every two weeks of dieting, produced more fat loss over 16 weeks of dieting than continuous restriction — so if your date is six months away, building in a maintenance week every month or two is not cheating, it is strategy. And if your goal date is more than a year out, break the goal into stages: reach the first 10 lb, hold it for a month, then set the next date. A date you hit beats a date you dread.
Written by the Live Fitness Check editorial team · Reviewed against our calculator methodology · Last updated November 2026
Disclaimer: This calculator is for general information only and is not medical advice. Weight-loss rates and calorie deficits are population guidance, not a personal recommendation. Talk to your doctor before starting a weight-loss plan if you are pregnant, take medication, have a history of disordered eating, or have diabetes, heart disease, or any condition that affects diet or exercise.
