Loading...
A 300 calorie deficit means eating 300 fewer calories than your body burns each day. For most men, this is a 11% deficit and results in approximately 0.6 lbs of fat loss per week. Your exact results depend on your TDEE (Total Daily Energy Expenditure), which varies based on weight, height, activity level, and body composition.
Last updated: February 8, 2026
The percentage deficit depends on your TDEE. Here is what a 300 calorie deficit represents for different TDEE values:
| Your TDEE | Percentage Deficit | Deficit Level | Difficulty | Weekly Change |
|---|---|---|---|---|
| 2,200 cal | 13.6% | Gentle | Easy | 0.6 lbs/week |
| 2,500 cal | 12% | Gentle | Easy | 0.6 lbs/week |
| 2,800 cal | 10.7% | Gentle | Easy | 0.6 lbs/week |
| 3,000 cal | 10% | Gentle | Easy | 0.6 lbs/week |
The same 300 calorie deficit has a different impact depending on your metabolic rate. Someone with a higher TDEE can handle this more easily than someone with a lower TDEE.
A 300 calorie deficit is not the same for everyone. It represents a larger percentage deficit for someone with a lower TDEE and a smaller percentage deficit for someone with a higher TDEE. For example, 300 calories is a 11% deficit for someone with a 2632 calorie TDEE, but only a 10% deficit for someone with a 3,000 calorie TDEE. The percentage matters because it determines how sustainable the deficit is and how much muscle you risk losing.
Your TDEE (Total Daily Energy Expenditure) is the number of calories your body burns in a day. It determines what a 300 calorie deficit actually means for you. Someone with a higher TDEE can handle a larger absolute calorie deficit without it being too aggressive. Someone with a lower TDEE needs to be more careful. Use FitCommit to calculate your exact TDEE based on your lean mass (measured via AI body scan) instead of relying on generic online calculators that only use weight and height.
Based on a 5'10", 180 lb man at moderate activity:
TDEE
2,624 cal
Percentage Deficit
11% Gentle
Daily Calories
2,324 cal
| Week | Weight | Body Fat % | Fat Mass | Lean Mass |
|---|---|---|---|---|
| Start | 180 lbs | 25% | 45 lbs | 135 lbs |
| Week 2 | 178.8 lbs | 24.6% | 44 lbs | 134.8 lbs |
| Week 4 | 177.6 lbs | 24.2% | 43 lbs | 134.6 lbs |
| Week 6 | 176.4 lbs | 23.8% | 41.9 lbs | 134.5 lbs |
| Week 8 | 175.2 lbs | 23.4% | 40.9 lbs | 134.3 lbs |
| Week 10 | 174 lbs | 22.9% | 39.9 lbs | 134.1 lbs |
For the reference man eating 2,324 calories per day:
2,324
Daily Calories
135g
Protein
300g
Carbs
65g
Fat
Women typically have lower TDEEs than men due to less lean mass, which means a 300 calorie deficit represents a larger percentage of their total expenditure. A 300 calorie deficit might be a 20% deficit for a 180 lb man (TDEE ~2,700 cal) but a 25% deficit for a 150 lb woman (TDEE ~2,000 cal). Women also tend to lose weight slightly slower due to hormonal differences and lower baseline metabolic rates. However, women have better fat oxidation efficiency during exercise, which can help offset the slower rate.
Adjust your calorie target every 4-6 weeks as you lose weight. Your TDEE drops as you get lighter, so what was a 300 calorie deficit at the start may only be a 200-100 calorie deficit later. Recalculate your TDEE and maintain the same calorie deficit to keep progress steady. If weight loss stalls for more than 2 weeks, drop calories by 100-150 and reassess after another week.
First, calculate your TDEE using a calculator or app. Then subtract 300 calories from your TDEE to get your daily calorie target. For example, if your TDEE is 2,500 calories, your target is 2200 calories per day. Use FitCommit to get your exact TDEE based on lean mass measured via AI body scan.
Optional. At this moderate deficit, cardio is helpful for health but not required for fat loss. If you enjoy it, 2-3 sessions of 20-30 minutes per week is plenty. Do not use cardio to create a larger deficit.
You can maintain a moderate deficit like this for 10-16 weeks. Most people see their best results within this timeframe. Take a 1-week diet break at maintenance after every 8-10 weeks.
Focus on whole foods: lean protein (chicken, fish, eggs, tofu), complex carbs (rice, oats, potatoes, bread), healthy fats (nuts, avocado, olive oil), and plenty of vegetables. Hit your protein target first (135-180g), then fill the rest with carbs and fats based on your calorie target. Track everything in a calorie counting app to ensure you hit your 300 calorie deficit consistently.
Stop guessing your TDEE based on generic calculators. FitCommit calculates your exact metabolic rate using your lean mass measured via AI body scan from your phone camera. Get personalized calorie targets in 60 seconds. Free 7-day trial.
Try FitCommit Free