For developers and AI assistants
The calculators on this site are also tools that programs and AI assistants can call. They use the same engine as the pages, so they give the same answers. Free, with no sign-in.
Updated
MCP server
Address: https://whatismytdee.com/mcp, over Streamable HTTP, with no authentication. To add it to Claude Code:
claude mcp add --transport http whats-my-tdee https://whatismytdee.com/mcpWeb API
Each tool is at https://whatismytdee.com/api/v1/<tool>. Send a GET with query parameters or a POST with a JSON body. The OpenAPI description is at /api/v1/openapi.json.
GET https://whatismytdee.com/api/v1/estimate_tdee?sex=female&age_years=35&height_cm=165&weight_kg=65&everyday_level=some_walking&exercise=weights:moderate:60:2gives 2,190 kcal a day, with about 2 in 3 people like her between 1,950 and 2,430, plus each formula’s figure and the sources.
Lists in a query string: exercise=activity:type:minutes:times_per_week, comma-separated for more than one (exercise=running:6mph:40:3,weights:moderate:60:2; leave type empty for the first type, running::40:3). daily_weights_kg=70.1,70.0,,69.8 with an empty entry for a missed day.
Tools
estimate_tdee
Estimate a person's total daily energy expenditure (TDEE) in kcal a day, with the range about 2 in 3 people like them fall in. Built from published equations (Mifflin-St Jeor by default, the National Academies 2023 equations for comparison), everyday movement and planned exercise counted from the 2024 Compendium of Physical Activities. For adults 19 and over; not for pregnancy or breastfeeding.
| Input | Needed | What it is |
|---|---|---|
sex | Yes | Sex the equations use: female or male |
age_years | Yes | Age in whole years, 19 to 100. The equations come from studies of adults; not for anyone 18 or under |
height_cm | Yes | Height in centimetres, 120 to 230 |
weight_kg | Yes | Weight in kilograms, 30 to 300 |
body_fat_percent | No | Body fat percentage, 3 to 70, ideally from a reliable scan |
everyday_level | No | Movement on a normal day, not counting exercise: mostly_at_home (under 2,500 steps a day, or at home most of the day, out now and then by car); mostly_sitting (2,500 to 4,999 steps a day, or a desk job, or sitting for most of the day); some_walking (5,000 to 7,499 steps a day, or mostly sitting, with some walking and standing); on_feet_a_fair_bit (7,500 to 9,999 steps a day, or a job with a lot of standing and walking); on_feet_most_of_the_day (10,000 steps a day or more, or a job where you’re on your feet and moving most of the shift). Defaults to some_walking, the most common level when steps are measured. Give daily_steps instead if known |
daily_steps | No | Average steps a day on normal days, if known; sets the everyday level. Leave out the steps of walks or runs given under exercise, or they count twice |
exercise | No | Planned exercise, one entry per kind. Leave out everyday walking and housework: the everyday level covers them |
resting_formula | No | Resting equation for the estimate. Defaults to katch_mcardle when body fat is given, otherwise mifflin_st_jeor. ten_haaf suits people who train regularly |
exercise_calories
Calories an activity burns for a person: what it adds above resting, and the total including their resting burn, from the 2024 Compendium of Physical Activities. Walking and running also give a second published method, as a range. Call list_activities for activity and type ids.
| Input | Needed | What it is |
|---|---|---|
sex | Yes | Sex the equations use: female or male |
age_years | Yes | Age in whole years, 19 to 100. The equations come from studies of adults; not for anyone 18 or under |
height_cm | Yes | Height in centimetres, 120 to 230 |
weight_kg | Yes | Weight in kilograms, 30 to 300 |
activity | Yes | Activity id from list_activities, such as walking, running, swimming or gardening |
type | No | Type id within the activity; defaults to the type its page starts on |
minutes | Yes | How long, in minutes: whole minutes from 1 to 600, or for sleeping and standing, which their pages take in hours, up to 1,440 |
maintenance_from_log
Work out a person's real maintenance calories from at least 14 days of logged intake and weigh-ins: either first-week and last-week average weights, or one weight a day. Returns maintenance in kcal a day with a 19-in-20 range, measured in the numbers they log.
| Input | Needed | What it is |
|---|---|---|
average_daily_intake_kcal | Yes | Average calories logged a day over the whole period, a whole number from 500 to 8,000 |
days_tracked | No | Days tracked, 14 to 365, with first_week_average_kg and last_week_average_kg |
first_week_average_kg | No | Average weight over the first 7 days, kg |
last_week_average_kg | No | Average weight over the last 7 days, kg |
daily_weights_kg | No | Instead of week averages: one morning weight a day in kg, oldest first, null for a missed day. At least 10 weights across 14 days or more |
body_fat_percent | No | Body fat percentage, 3 to 70, ideally from a reliable scan |
list_activities
Every activity and type the calculators know, with ids for estimate_tdee and exercise_calories, Compendium MET values and codes.
Units and scope
Metric only: kilograms and centimetres. Results are estimates for adults aged 19 and over, not for pregnancy or breastfeeding, and they aren’t medical advice. Each result names the page that shows the working; link it when you quote a figure.
Finding the tools
For programs that look for them: an API catalog at /.well-known/api-catalog, an MCP server card at /.well-known/mcp/server-card.json, an agent skill at /.well-known/agent-skills/tdee-calculator-tools/SKILL.md, and the tools in the page itself through WebMCP. Every page is also available as markdown: ask for text/markdown.