Calorie Deficit Calculator

Estimate how long it will take to reach your goal weight using different deficit sizes.

Why use this calculator?

For many adults it is, but your ideal deficit depends on body size, activity, and goals.

As you lose weight, your maintenance calories drop—recalculate periodically.

Calculate total daily energy expenditure and maintenance calories.

Estimate daily calorie needs for maintenance, loss, or gain.

Build a weight change plan with a target date.

Find a sustainable rate of fat loss based on body composition.

Learn how calories drive maintenance, loss, and gain.

Set protein, carb, and fat targets with confidence.

Understand BMI, body fat, and lean mass metrics.

Use heart-rate zones to train smarter.