Calorie Deficit Percentage Calculator

Check how large your planned calorie deficit is relative to estimated maintenance, then compare it with common 10%, 15%, and 20% planning ranges before using it.

Maintenance-based deficit10%, 15%, 20% comparisonSurplus detected too
Check the size of the adjustment.A 300 kcal gap can be small or large depending on maintenance. This calculator turns the gap into a percentage.
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What This Calculator Shows

This tool converts a calorie gap into a percentage of estimated maintenance. Percentage framing is useful because the same 300 kcal gap means different things for different maintenance levels.

Formula Used

Deficit percentage = (maintenance calories - planned intake) / maintenance calories x 100

If planned intake is above maintenance, the calculator reports a surplus percentage instead.

Common Deficit Examples

Maintenance10% Deficit15% Deficit20% Deficit
1,800 kcal1,620 kcal1,530 kcal1,440 kcal
2,400 kcal2,160 kcal2,040 kcal1,920 kcal
3,000 kcal2,700 kcal2,550 kcal2,400 kcal

How To Interpret The Percentage

Below 10%Conservative and often easier to sustain, but progress can be subtle.
10% to 20%Common planning range for many adults, still requiring trend review.
Above 20%A larger adjustment that deserves caution, especially if energy or training drops.

Frequently Asked Questions

How do I calculate calorie deficit percentage?

Subtract planned intake from estimated maintenance, divide by estimated maintenance, then multiply by 100.

What is a 500 calorie deficit as a percentage?

It depends on maintenance. A 500 kcal gap is about 21% of 2,400 kcal maintenance, but about 17% of 3,000 kcal maintenance.

What if my intake is above maintenance?

The calculator reports a surplus target instead of a deficit, using the same percentage logic.

Is a 20% deficit always better than 10%?

No. A larger deficit may be harder to sustain and can affect hunger, training, mood, and adherence. The smallest effective adjustment is often easier to evaluate.

Can this predict weekly fat loss?

No. It only shows planned deficit size. Real trends depend on tracking accuracy, water shifts, activity, metabolism, and adherence.