Loading...
Version 2 is almost here. V2 coming soon. Join 500+ users before launch.Download now
How long to lose 20 lbs for women depends on your weekly pace and daily calorie deficit. At 1 lb per week (500 cal/day deficit), it takes 20 weeks. At 2 lbs per week (1,000 cal/day deficit), it takes 10 weeks. The table below shows all four common paces with exact numbers.
Each row shows how long it takes to reach your goal at a given weekly pace and the daily calorie deficit required. 1 lb of fat = 3,500 calories.
| Pace | Daily Deficit | Weekly Deficit | Weeks | Months |
|---|---|---|---|---|
| 0.5 lb/week | 250 cal/day | 1,750 cal/wk | 40 wks | 9.2 mo |
| 1 lb/week(recommended) | 500 cal/day | 3,500 cal/wk | 20 wks | 4.6 mo |
| 1.5 lb/week | 750 cal/day | 5,250 cal/wk | 13 wks | 3 mo |
| 2 lb/week | 1,000 cal/day | 7,000 cal/wk | 10 wks | 2.3 mo |
One pound of stored body fat contains approximately 3,500 calories of energy. This is the foundation of weight loss math. To lose 20 lbs, you need to create a total calorie deficit of 70,000 calories.
2,000
Average female TDEE (cal/day)
-500
Daily deficit for 1 lb/wk
1,500
Target intake (cal/day)
These numbers are based on an average female TDEE. Your exact target depends on your current weight, height, age, and activity level. Use the FitCommit app to calculate your personalized TDEE from an AI body scan.
20 lbs of fat = approximately 14.0% body fat reduction for an average female.
This estimate uses a reference body weight of 140 lbs (female). If you weigh more, each pound of fat represents a smaller percentage reduction in your body fat. If you weigh less, each pound represents a larger percentage. Use a body fat measurement tool to track your actual composition, not just scale weight.
A 500 calorie daily deficit from a 2000 calorie TDEE means eating 1500 calories per day
A 750 calorie daily deficit from a 2000 TDEE means eating 1250 calories per day and losing 1.5 lbs per week
Cutting 500 calories through food and burning 250 calories through walking (45-60 min) creates a 750 calorie combined deficit
Eliminating processed snacks, sugary drinks, and alcohol can create a 500-700 calorie daily deficit without changing meals
0.5-1 lb/week. Lower deficit, better muscle retention, easier to sustain. Best for lean individuals or those new to dieting.
1.5-2 lbs/week. Larger deficit, faster results, more hunger and higher muscle loss risk. Requires careful protein intake and consistent training.
Week 4: ~4 lbs lost
Water weight drop is mostly complete. True fat loss now shows on the scale. Energy may be slightly lower than normal. This is normal and improves as your body adapts to the deficit.
Week 8: ~8 lbs lost
Visible changes in clothing fit and body shape. First plateau may appear around this time. If progress stalls, take a 1-week maintenance break to reset hunger hormones, then return to your deficit.
Week 12: ~12 lbs lost
Significant physique changes visible. Recalculate your TDEE at this point, since a lighter body burns fewer calories. Adjust your daily calorie target down by 50-100 calories if weight loss has slowed more than expected.
The timelines above use average TDEE numbers. Your actual timeline depends on your personal TDEE, which requires knowing your lean mass. FitCommit scans your body using your phone camera to measure body fat percentage and lean mass, then calculates your exact daily calorie target. You get a personalized deficit number, macro breakdown, and food scanning to track every meal. No guessing.
A calorie deficit means consuming fewer calories than your body burns. For a woman with a 2000 calorie TDEE, a 500 calorie daily deficit means eating 1500 calories per day. You can create this through food reduction alone, exercise alone, or a combination. Tracking calories with an app is the most reliable method. Guessing portions consistently leads to underestimating intake by 20-40%.
Minimal muscle loss is expected with a moderate deficit (500-750 cal/day). Eating at least 1g of protein per pound of lean body mass and maintaining resistance training preserves most muscle during fat loss. At 1 lb/week, your body has time to adapt without aggressively breaking down muscle tissue.
Plateaus are normal. Your metabolism adapts to lower calorie intake and weight loss slows. The first plateau typically hits around weeks 6-8. Do not cut calories further. Instead, take a 1-week diet break at maintenance calories. This resets hunger hormones (leptin and ghrelin) and restores metabolic rate. After the break, return to your deficit. Also recalculate your TDEE every 4-6 weeks as your weight drops, since a lighter body burns fewer calories.
The fastest safe rate of fat loss is 1.5-2 lbs per week, which requires a 750-1,000 calorie daily deficit. Beyond 2 lbs per week, the risk of muscle loss increases significantly and adherence drops. To speed up safely: (1) Track calories precisely with an app. (2) Increase protein to 1g per lb of lean mass. (3) Add 2-3 sessions of low-intensity cardio per week (walking, cycling). (4) Prioritize sleep, since poor sleep increases hunger hormones by 20-30%.
Get your personalized calorie target based on your actual lean mass, not averages. AI body scan, food tracking, and macro breakdown. Free 7-day trial.
Try FitCommit Free