How many calories is one pound of fat?

One pound of body fat contains approximately 3,500 kilocalories. To lose one pound per week you need a total weekly deficit of 3,500 kcal, which equals a daily deficit of 500 kcal.

What is a safe maximum daily deficit?

Most health authorities recommend a deficit no larger than 500–1,000 kcal per day, equating to 1–2 lb (0.45–0.9 kg) of loss per week. Larger deficits increase the risk of muscle loss, nutrient deficiencies, and metabolic adaptation.

What is TDEE and how do I find mine?

TDEE (Total Daily Energy Expenditure) is the total number of calories your body burns in 24 hours, including exercise and daily activity. Use a TDEE calculator that factors in your age, sex, height, weight, and activity level to estimate yours.

Why is there a minimum calorie floor?

Eating fewer than roughly 1,200 kcal/day (women) or 1,500 kcal/day (men) can cause the body to break down muscle for fuel, lead to nutrient deficiencies, and slow metabolism. The calculator flags these situations so you can extend your timeline instead.

Does the 3,500 kcal-per-pound rule always hold?

It is a reliable approximation for most people over weeks to months, but individual metabolic adaptation, water retention, and body composition changes mean real-world results can vary. Reassess your TDEE every 4–6 weeks as your weight changes.

Can I use this calculator to plan a calorie surplus for muscle gain?

This tool is designed for weight loss deficits. For muscle gain, use a TDEE-based surplus calculator and apply the same principle in reverse — a modest surplus of 200–300 kcal/day is typical for lean bulking.

Daily Calorie Deficit Calculator

Name: Daily Calorie Deficit Calculator
Availability: InStock
Author: Nham Vu

Enter your TDEE and weight loss goal to find exactly how many calories to cut each day to hit your target on time.

Your Details

Unit System

Your TDEE (kcal/day)

Total Daily Energy Expenditure — use a TDEE calculator if unsure.

Weight Loss Goal (lb)

Timeframe (weeks)

Biological Sex (for minimum calorie check)

Fill in your details and click Calculate Deficit to see your plan.

Summary

Enter your TDEE and weight loss goal to find exactly how many calories to cut each day to hit your target on time.

How it works

Enter your current TDEE — the total calories your body burns in a day.
Select your unit system (pounds or kilograms) and input your weight loss goal.
Choose how many weeks you want to achieve that goal in.
The calculator multiplies your goal by 3,500 kcal/lb (or 7,700 kcal/kg) to get the total deficit needed.
It divides that total by the number of days to give your required daily deficit.
Your recommended daily intake is TDEE minus the daily deficit, with a safety floor check.

Use cases

Plan a calorie budget before starting a structured diet program.
Check whether your current deficit is aggressive enough to hit a goal date.
Verify that a planned intake is above safe minimum thresholds.
Compare different timeframes to choose a pace that fits your lifestyle.
Adjust targets mid-diet when progress stalls or accelerates.
Combine with a macro calculator to split intake into protein, carbs, and fat.
Coach clients on realistic fat-loss timelines based on their TDEE.
Understand why slow-and-steady beats crash dieting for sustainable results.

Frequently Asked Questions

Last updated: 2026-07-01 · Reviewed by Nham Vu