Calculator
What the Calorie Surplus Calculator does
Calorie Surplus Calculator: calculates Maintenance Calories (TDEE), Daily Surplus Needed and Target Daily Calories from Your Weight, Your Height and Your Age. Example: your weight 65 kg, your height 170 cm and your age 25 years gives maintenance calories (TDEE) 1,911.
Give the Calorie Surplus Calculator your Your Weight, Your Height, Your Age and Sex and it works out Maintenance Calories (TDEE), Daily Surplus Needed and Target Daily Calories. Adjust anything and the figures re-derive on the spot.
Most people who open the Calorie Surplus Calculator are readers checking a number from a clinic. Knowing how a figure is derived makes it much easier to interpret sensibly.
Nothing leaves the tab. You can watch your browser network panel while you use it and see for yourself.
The field table, the method and a worked example are documented after the tool for anyone who wants to check the working.
What do the Calorie Surplus Calculator fields mean?
The Calorie Surplus Calculator uses 6 inputs. A filled form means you can test one idea immediately instead of sourcing every input first.
| Field | What to enter | Default |
|---|---|---|
| Your Weight | measured in kg; accepts 30 to 250 | 65 |
| Your Height | measured in cm; accepts 100 to 230 | 170 |
| Your Age | measured in years; accepts 15 to 90 | 25 |
| Sex | choose from Male or Female | Male |
| Daily Activity Level | choose from Sedentary (desk job, little exercise), Lightly active (1 to 3 days/week), Moderately active (3 to 5 days/week), Very active (6 to 7 days/week) or Extra active (hard training / physical job) | Sedentary (desk job, little exercise) |
| Target Weekly Weight Gain | choose from 0.125 kg/week (very lean gain), 0.25 kg/week (recommended for lean bulking), 0.5 kg/week (moderate) or 0.75 kg/week (aggressive) | 0.125 kg/week (very lean gain) |
How does the Calorie Surplus Calculator work?
Each output is derived from the inputs above in a single pass; there is no hidden state carried between runs, so the same inputs always give the same calculation.
An empty or malformed field stops the calculation rather than being treated as zero.
Worked example
These are the values the Calorie Surplus Calculator loads by default, and the result it produces from them. Below is the same computation the tool performs on load, step by step.
| Your Weight | 65 kg |
|---|---|
| Your Height | 170 cm |
| Your Age | 25 years |
| Sex | Male |
| Daily Activity Level | Sedentary (desk job, little exercise) |
| Target Weekly Weight Gain | 0.125 kg/week (very lean gain) |
| Maintenance Calories (TDEE) | 1,911 |
|---|---|
| Daily Surplus Needed | 137.5 |
| Target Daily Calories | 2,048.5 |
| Reality Check | This pace is close to what well-trained lifters can plausibly gain as muscle, but genetics, training and protein… |
| Plan | Eat about 2049 kcal/day: a 138 kcal/day surplus above your ~1911 kcal maintenance (TDEE): to gain roughly 0.125… |
Read next: BMR and TDEE: Why Every Calculator Gives You a Different Number
How to use it
- Set Your Weight in kg (30 to 250).
- Put Your Height in cm (100 to 230).
- Key in Your Age in years (15 to 90).
- Pick a value for Sex: the options are Male or Female.
- Pick a value for Daily Activity Level: the options are Sedentary (desk job, little exercise), Lightly active (1 to 3 days/week), Moderately active (3 to 5 days/week), Very active (6 to 7 days/week) or Extra active (hard training / physical job).
- Pick a value for Target Weekly Weight Gain: the options are 0.125 kg/week (very lean gain), 0.25 kg/week (recommended for lean bulking), 0.5 kg/week (moderate) or 0.75 kg/week (aggressive).
- Because there is no round trip to a server, updating on every keystroke costs nothing.
- Check Maintenance Calories (TDEE), Daily Surplus Needed, Target Daily Calories, Reality Check and Plan on the right.
- Copy Link when you want to return to this exact configuration; Print when someone needs it on paper.
What this tool does not do
- These formulas come from population averages and cannot account for your medical history.
- This is a screening estimate, not a diagnosis.
- Where a standard has revisions, the version used is the one named in the method section.
- The tool trusts your numbers completely, so a mis-keyed digit propagates straight through.
Frequently asked questions
Enter Your Weight in kg, Your Height in cm and Your Age in years. Every input names its unit, and every output does too, which removes the usual source of error.
Your Weight accepts 30 to 250 kg. Go outside it and you get an error against that specific field instead of a misleading number.
With the values loaded when the page opens, maintenance calories (TDEE) comes out as 1,911. Adjust any field to see how much the answer depends on it.
No. Your browser is doing the computing, so we could not see the values even if we wanted to.
No charge. Everything on the page is available without signing in.
The computation is exact. What it is computing is a population average, which is a different thing from a fact about you, so read the number as a prompt to ask a better question.