Intermittent Fasting Calculator Based on Weight

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Essential fields

Goal settings

BMR

1729 kcal/day

TDEE (maintenance)

2680 kcal/day

Target daily calories

2130 kcal/day

Calories per meal

1065 kcal

Estimated weeks to goal

14.0 weeks

Eating window (hours)

8h

Protein

156 g/day

Carbs

215 g/day

Fat

72 g/day

Daily water target

2870 mL/day

Calorie breakdown

Macro split

Weight projection

Shows a realistic line (your chosen pace) and an aggressive comparison line.

Calculator by CalculatorNut

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How to Use

Enter anthropometrics, sex, activity, and desired daily calorie deficit. Review TDEE, target calories, and a rough per-hour eating-window split.

Formula

BMR (Mifflin–St Jeor) × activity factor − daily deficit = target intake; optional per-hour split for an 8-hour window.

Intermittent fasting calories guide (weight-based)

Use your stats to estimate BMR and TDEE, set a safe deficit or surplus, and generate calories per meal plus macro grams for your fasting window.

What this page answers

Once your fasting window is chosen, the next question is nutrition: how many calories should you eat, and how should you distribute protein, carbs, and fat. This calculator estimates maintenance calories (TDEE), applies a goal-based adjustment, and splits your daily target into meals.

Why multiple charts help

  • Calorie donut: shows how maintenance is built from BMR + activity and your deficit/surplus.
  • Macro donut: turns percentages into something actionable (grams).
  • Weight projection: makes timelines realistic and motivating.

A note on safety

Very aggressive deficits can reduce adherence and performance. Use the warning banner as a hint to slow the pace and prioritize protein and sleep.

FAQ

Is TDEE exact?
No—metabolism varies; treat as a starting estimate.
Should I eat the same every day?
Weekly averages often matter more than single days.
What about protein?
Use our keto macro tool or a dietitian for macro planning.

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