BMR (Harris-Benedict) Calculator
The formula
What the bmr (harris-benedict) tells you
The calorie floor and ceiling for bmr (harris-benedict): resting burn plus lifestyle, from the Mifflin-St Jeor equation — the one dietetic bodies still endorse.
Calculation: Mifflin-St Jeor BMR = 10w + 6.25h − 5a + 5 (men) −161 (women); TDEE = BMR × activity. Enter your inputs and every substitution is shown below the result.
Reading the result
±10 % is the honest error band; nudge the target up or down by 200 kcal after two weeks on the scale.
Limitations and best practice
Activity multipliers flatter everyone — if weight is static, the true multiplier is the lower one.
This calculator gives an estimate based on standard formulas; it is not professional financial, medical, legal or engineering advice. Verify anything you plan to act on with a qualified professional and your own records.
Frequently asked questions
Why not Harris-Benedict?
How fast should I lose?
Source & methodology
Mifflin-St Jeor (1990), ADA-endorsed.
How BMR (Harris-Benedict) works — and what your result really means
You are here because you need a specific number, and you want to see how it was produced before you rely on it. Searchers land on a BMR (Harris-Benedict) page for three reasons — to plan, to compare options, and to check that somebody else’s arithmetic is honest. This tool serves all three, and everything after the calculator explains the model instead of hiding it.
A calculation like this one is worth roughly as much as a careful sentence: it forces several vague considerations into one comparable quantity. Once BMR (Harris-Benedict) is on the table, the argument can stop being about impressions.
There is a habit that separates people who get useful answers from Nutrition numbers: they decide what question the figure answers before they compute it. BMR (Harris-Benedict) answers “Daily maintenance (TDEE)?” — and nothing else, which is precisely why the result is trustworthy.
Nothing below is stock text pasted around a number: the worked example computes daily maintenance (TDEE) = 3,224 kcal from this tool’s own defaults, and the sensitivity section ranks the inputs that move the result — Weight first, at ≈6.2 % of the headline for a ten-percent error either way in that input — which is the thread the rest of this guide pulls on.
Every input in BMR (Harris-Benedict), and what it does to the answer
The engine implements a single stated model: Mifflin-St Jeor BMR = 10w + 6.25h − 5a + 5 (men) −161 (women); TDEE = BMR × activity. There is no hidden coefficient and no login-gated precision — the formula printed is the formula executed, which is also what makes the result citable.
Weight (kg) (example value 145) is a quantity rather than a category — precision here is cheap and worth having. Use the same conditions each time (same scale, same time of day) so that changes in the output reflect real change.
Height (cm) (example value 168) is a plain measured quantity — the unit shown in the label is the unit the formula expects. Keep every length field in the same unit; the formula assumes a consistency it cannot check for you.
Age (years) (example value 32) is a numeric input whose unit is fixed by the label; a wrong unit is a wrong answer wearing a plausible disguise. Use the value as of today, not as of the last time you looked — time fields drift silently.
Sex (example value Male) is a selector, not a measurement: the engine follows a different route for each option. The example value is there to demonstrate the mechanics, not to describe your situation — overwrite it.
Activity multiplier (example value Light (1–3×/wk)) is a selector, not a measurement: the engine follows a different route for each option. This input feeds the formula directly; a defensible figure here is worth more than false precision anywhere else.
What each “Sex” choice actually does: Male → 3,224 kcal · Female → 2,996 kcal — each value above is the model’s own output for that option, so the choice can be made on evidence rather than on what a category feels like it means.
What each “Activity multiplier” choice actually does: Sedentary → 2,814 kcal · Light (1–3×/wk) → 3,224 kcal · Moderate (3–5×) → 3,635 kcal · Hard (6–7×) → 4,045 kcal · Athlete / physical job → 4,456 kcal That table is the honest answer to “does this option matter”, re-derived from the formula rather than hard-coded into page copy.
A fully worked BMR (Harris-Benedict) example
Rather than describe the calculation, here it is end to end — every substitution in order, starting from the inputs above. Starting figures: Weight (kg), Height (cm), Age (years), Sex. The computed daily maintenance (TDEE) comes out at 3,224 kcal, which the interpretation band labels “High demand — fueling plans matter as much as training”.
- BMR = 10×145 + 6.25×168 − 5×32 + 5 = 2,345 kcal
- TDEE = 2,345 × 1.375 = 3,224 kcal
BMR (coma calories) — 2,345 kcal. Read next to the headline, this is the figure that shows the shape of the trade-off.
Per kg bodyweight — 22 kcal/kg. Read next to the headline, this is the figure that shows the shape of the trade-off.
Protein anchor (1.6 g/kg) — 232.0 g. If your inputs change, this is usually the first companion figure to move.
Overwrite any input above and every line of this example updates with it — the substitution is live, not a screenshot of somebody else’s numbers.
The BMR (Harris-Benedict) corridor: your result across a realistic band
The honest version of any estimate is a corridor, and this one is cheap to produce: BMR (Harris-Benedict) was recomputed at 5 points along the dominant input, with every other field left untouched.
| Weight setting | Daily maintenance (TDEE) |
|---|---|
| 80 % of the example value | 2,826 kcal |
| 90 % of the example value | 3,025 kcal |
| example inputs | 3,224 kcal |
| 110 % of the example value | 3,424 kcal |
| 120 % of the example value | 3,623 kcal |
That spread — 2,826 kcal at the low end, 3,623 kcal at the high — is what a careful read of BMR (Harris-Benedict) looks like: a band you can state out loud, with the reason for each edge. Reproduce it in the form above by editing Weight alone; the substitution steps will follow your figures exactly.
What actually moves your BMR (Harris-Benedict)
Generic advice says “it depends on your inputs”; this section says exactly how much. Each field was perturbed by ±10 % in isolation and the daily maintenance (TDEE) recomputed, so the ranking below is measured rather than asserted. It is the fastest honest answer to “what matters most in BMR (Harris-Benedict)?” — and it is specific to these defaults, because sensitivity moves with the starting point.
- Weight: ten percent up gives 3,424 kcal, ten percent down gives 3,025 kcal — ≈6.2 % of the daily maintenance (TDEE) either way
- Height +10 % → BMR (Harris-Benedict) = 3,369 kcal · −10 % → 3,080 kcal (the daily maintenance (TDEE) shifts ≈4.5 %)
- Age +10 % → BMR (Harris-Benedict) = 3,202 kcal · −10 % → 3,246 kcal (the daily maintenance (TDEE) shifts ≈0.7 %)
Weight is the dominant lever here: ten percent either way moves the result by about 6.2 %, from 3,025 kcal to 3,424 kcal. Measure that input from a document rather than from memory, and treat Height as the second priority (≈4.5 % per ten percent). Everything below that can stay approximate, which is a licence to stop chasing data that would not change the decision.
What a BMR (Harris-Benedict) of 3,224 kcal means in practice
Nobody acts on a bare figure — they act on a figure with a comparison attached. The verdict attached to the default calculation — “High demand — fueling plans matter as much as training” — is one band on a ladder your own figure may sit somewhere else on. The sensitivity list shows how far a modest input error moves you along that ladder: for Weight, ±10 % covers 3,025 kcal to 3,424 kcal. The practical reading rules: compare against your own history before comparing against other people; treat band boundaries as zones, not walls — one point on the wrong side of a threshold rarely changes a real outcome; and when a companion output contradicts the headline, believe the pair.
The comparison worth making is not with somebody else’s BMR (Harris-Benedict) but with the version of your own situation measured last quarter — same formula, same conventions, different inputs.
The errors that quietly break a BMR (Harris-Benedict) figure
Activity multipliers flatter everyone — if weight is static, the true multiplier is the lower one. This calculator gives an estimate based on standard formulas; it is not professional financial, medical, legal or engineering advice. Verify anything you plan to act on with a qualified professional and your own records.
Copying a single headline number without checking the companion outputs. The tool reports BMR (coma calories), Per kg bodyweight and Protein anchor (1.6 g/kg) alongside the main result precisely because BMR (Harris-Benedict) in isolation misleads — the secondary columns are where outliers and trade-offs show up.
One mistake is specific to this engine: assuming every input matters equally. The computation above shows Weight dominating — a careful figure there beats false precision everywhere else.
Another is comparing across contexts: a BMR (Harris-Benedict) computed with one set of conventions should never be lined up against a figure computed with another. Check the inputs behind both before ranking them.
A quick check for any BMR (Harris-Benedict) figure
- Compare the result with one independent method or published benchmark.
- State, in one sentence, which convention each rate, unit or period in the form is using.
- Put Weight under a magnifier; the sensitivity table above is the reason why.
- Confirm the example values are plausible for your own situation before replacing them.
- Compare the output against one published benchmark or a colleague’s independent estimate.
- Run the ±10 % stress on the top two levers and check that your conclusion survives both.
A routine for decision-grade BMR (Harris-Benedict)
The tool does the arithmetic; the routine below is what makes the arithmetic trustworthy. Five steps, a minute total — and afterwards you will know not just what the number is, but which assumption produced it.
Step 1 — start from evidence. The inputs behind BMR (Harris-Benedict) are weight (kg), height (cm), age (years), sex, activity multiplier. Write them down with their source next to each one; if you cannot name where a figure came from, that is the input most likely to be wrong. If a result feels obviously right, that is the moment to check the inputs hardest.
Step 2 — baseline before exploration. Get one defensible Daily maintenance (TDEE) on screen before you start nudging numbers. Without a baseline, every variation looks interesting and none of them means anything. Repeating a calculation with the same numbers proves only that the arithmetic is reliable — which is worth knowing.
Step 3 — isolate your variables. Change one field, observe, revert. The live sensitivity list does the ranking for the default inputs; verify it against your own, because dominance shifts when the starting point shifts. When in doubt, prefer the boring input: the interesting one is usually the one you misread.
Step 4 — compute a corridor, not a point. Three runs — worst, likely, best — turn BMR (Harris-Benedict) from a snapshot into a range. Plan against the pessimistic end and treat the optimistic end as the upside story. If the verdict changes with a ten-percent nudge, report the nudge alongside the number.
Step 5 — write the one-line memo. “Daily maintenance (TDEE) = 3,224 kcal on this date, from these inputs.” That line is the entire deliverable; everything else on this page is how you earned the right to write it. If the answer changes your behaviour, it deserves a second run with different assumptions.
From calculation to decision: where BMR (Harris-Benedict) earns its keep
Numbers earn their keep in conversations, and BMR (Harris-Benedict) is no exception. In Health & Medical discussions around Nutrition, this figure decides whether an option stays on the table: it converts an opinionated debate into an arithmetic one, and arithmetic is the only referee both sides accept. One decimal place more than your data supports is one decimal place of fiction.
Professionals in Nutrition use this style of calculation as a screening filter before spending real money or effort: a quick BMR (Harris-Benedict) check eliminates weak options in minutes, and the survivors earn the deeper, slower analysis. The point of transparency is that a reader can disagree with a specific line rather than with you.
Treat BMR (Harris-Benedict) like a smoke alarm rather than a painting — its value is in being tested periodically, not in being admired once. Note the assumption you are least sure about; that is where the real risk lives.
People also ask about BMR (Harris-Benedict)
What affects BMR (Harris-Benedict) the most?
Measured on this engine, Weight is the dominant lever: moving it ±10 % shifts the daily maintenance (TDEE) across 3,025 kcal to 3,424 kcal — about 6.2 % of the headline, with Height next at ≈4.5 %. The ranked list in the sensitivity section is computed live, not asserted from a template.
Which matters more: height or weight?
By the numbers, Weight: a ten-percent change in it moves the result ≈6.2 %, versus ≈4.5 % for Height. Spend your measuring effort in that order — precision on the weaker lever buys almost nothing.
How much does the “Sex” choice change the answer?
The spread is not cosmetic: this choice alone takes BMR (Harris-Benedict) from 2,996 kcal to 3,224 kcal with every other input frozen, which is more influence than most of the numeric fields on this page can claim.
What is a typical BMR (Harris-Benedict)?
On the worked example above BMR (Harris-Benedict) comes out at 3,224 kcal. Treat that as one point on a distribution rather than a norm: the bands, the companion outputs and the sensitivity ranking tell you how wide the plausible range really is.
How do I calculate BMR (Harris-Benedict) by hand?
Three steps: write the formula (Mifflin-St Jeor BMR = 10w + 6.25h − 5a + 5 (men) −161 (women); TDEE = BMR × activity), insert your values, and simplify. The worked example section shows exactly that chain for the default inputs; replicating it once on paper teaches you more about BMR (Harris-Benedict) than any number of calculator runs.
What happens to BMR (Harris-Benedict) if weight changes by 10 %?
On these inputs a ±10 % change in weight takes BMR (Harris-Benedict) to 3,424 kcal against the 3,224 kcal example — around 6.2 % of the headline. The same test on every other field is in the sensitivity section.
Is the BMR (Harris-Benedict) result of 3,224 kcal good or bad?
Neither, on its own — the label “High demand — fueling plans matter as much as training” is the band this figure falls in for the example inputs, and your own inputs will place you elsewhere on the same ladder. Judge the number against your history and your alternatives, and remember that a ten-percent error in Weight alone moves it by ≈6.2 %.
How accurate is BMR (Harris-Benedict) for me personally?
The formula encodes averages; body-composition and measurement error typically shifts results by a few percent in either direction. Use ranges and trends, and treat any single 3,224 kcal as approximate.
Can BMR (Harris-Benedict) be negative or empty?
Yes, and that is informative rather than broken: a negative BMR (Harris-Benedict) usually means the inputs encode an outflow or a shortfall, and the verdict band above labels exactly that situation instead of hiding it.
Why not Harris-Benedict?
Original H-B runs hot for modern populations; revised H-B lands within a point or two of Mifflin for average builds.
How fast should I lose?
0.5–1 % of bodyweight per week preserves muscle; beyond that the deficit starts eating lean mass.
Is my data private on this page?
Yes — computation happens locally in your browser, with no account, no tracking of your inputs and nothing sent to a server. The printed formula is the whole story of what happens to your figures.
Glossary for BMR (Harris-Benedict)
- BMR (coma calories)
- 2,345 kcal for the BMR (Harris-Benedict) worked case; it sits next to the main result because it carries context the headline leaves out.
- Per kg bodyweight
- 22 kcal/kg in the default BMR (Harris-Benedict) calculation — one of the secondary figures an experienced reader checks before trusting the primary number.
- Protein anchor (1.6 g/kg)
- 232.0 g in the default BMR (Harris-Benedict) calculation — one of the secondary figures an experienced reader checks before trusting the primary number.
- Daily maintenance (TDEE)
- The primary output of this tool: 3,224 kcal for the default inputs, computed exactly from Mifflin-St Jeor BMR = 10w + 6.25h − 5a + 5 (men) −161 (women); TDEE = BMR × activity.
- Worked example
- The step-by-step substitution printed above, so the arithmetic can be re-derived by hand or in a spreadsheet.
- Verdict band
- The plain-language label — here “High demand — fueling plans matter as much as training” — mapping the computed figure onto experience-based ranges for Health & Medical.
- Sensitivity (±10 %)
- How far the BMR (Harris-Benedict) moves when a single input is nudged ten percent either way; the ranked list on this page is computed live from this engine.
Where the BMR (Harris-Benedict) model comes from
There is no black box on this page — the engine evaluates Mifflin-St Jeor BMR = 10w + 6.25h − 5a + 5 (men) −161 (women); TDEE = BMR × activity. Source of record: Mifflin-St Jeor (1990), ADA-endorsed. Where a professional version of this calculation differs, it differs in inputs and jurisdiction-specific coefficients, not in the algebra — which is why re-checking your inputs beats hunting for a second calculator.
Nothing here replaces a qualified professional, and nothing here is approximate either — the arithmetic is exact, and the honesty is in the inputs you supply. Nothing is smoothed, weighted or adjusted behind the scenes; where judgement enters, this page says so and names the input responsible.
Next steps after the calculation
Re-run the calculation with your own figures, stress the two most sensitive inputs by ±10 %, and only then act on the result.
This page was written for people who need one trustworthy number before their next decision, and the promise is that nothing above required trust. Bookmark the tool, re-run it whenever an input moves by more than a few percent, and keep the date with the number.