How fast should I gain weight?

A gradual pace of about 0.25–0.5 kg (0.5–1 lb) per week is generally recommended to favor muscle gain over excess fat, especially when paired with strength training.

What if my timeframe is too short?

If your timeframe requires gaining faster than 1 kg per week, the calculator will flag it — try extending your timeframe for a more sustainable pace.

How do I turn the surplus into a meal plan?

Add the daily surplus shown to your maintenance calories (from the TDEE Calculator) to get a daily calorie target to guide your food intake.

Health & Fitness

Weight Gain Calculator

Enter your current weight, goal weight, and a timeframe to see the weekly gain rate and daily calorie surplus needed to reach your goal.

Your calculation is performed in your browser.

Enter your current weight, goal weight, and timeframe above.

This result is an estimate for informational and educational purposes. It isn’t a diagnosis and isn’t a substitute for advice from a doctor, registered dietitian, or other qualified professional. See our methodology and sources for the formula used and its limitations.

How it works

The calculator divides the total weight you want to gain by your chosen timeframe to find the required weekly gain rate, then converts that rate into a daily calorie surplus using the standard energy value of body tissue gain. It flags timeframes that would require an unusually fast rate of gain.

Formula & methodology

The total weight to gain is spread evenly over your timeframe to give a weekly rate. That rate is converted into a daily calorie surplus using about 7,700 calories per kg (3,500 per lb). Plans needing more than 1 kg (2.2 lb) per week are rejected as too fast.

Total to gainTotal to gain = Goal weight − Current weight

Weekly rateWeekly rate = Total to gain ÷ Weeks

Daily surplusDaily surplus = Weekly rate × Calories per unit ÷ 7

What each term means

Weeks: Your chosen timeframe.
Calories per unit: 7,700 per kg, or 3,500 per lb.

Worked example

Gaining 6 kg over 24 weeks requires a rate of 0.25 kg per week, which needs a daily calorie surplus of about 275 calories.

Common uses

—Planning a lean bulk timeline that favors muscle gain over excess fat.
—Setting a realistic weight-gain rate for underweight individuals working with a professional.
—Turning a goal weight and timeframe into a concrete daily calorie surplus.

Important notes

—The calculator will not accept a timeframe that requires gaining more than 1 kg (about 2.2 lb) per week, since faster gains tend to add proportionally more fat than lean mass.
—Pairing a calorie surplus with resistance training generally leads to a higher proportion of the gain being muscle rather than fat.