How to Calculate My TDEE by Hand, Step by Step

To calculate my TDEE by hand, I put age in years, height in cm and weight in kg into the 2023 NASEM equation, using the row for sex and activity. A woman who is 36, 167.6 cm and 69.9 kg and picks “low active” gets 2,278 kcal a day. Treat any result as an estimate, because the equation’s error runs to a few hundred kcal.

How do I calculate my TDEE by hand?

Four steps, and a pen is enough. (If the term itself is new, what TDEE is comes first.) Convert your units, pick an activity row, run the sum, then test the result against your scale.

Units come first. The NASEM equation wants kilograms and centimeters. Pounds × 0.4536 gives kg, and inches × 2.54 gives cm. My example woman is 154 lb and 5 ft 6 in (66 in), which is 69.9 kg and 167.6 cm. The example man is 190 lb and 5 ft 11 in, which is 86.2 kg and 180.3 cm. Age is in whole years.

The equations are the adult coefficients from NASEM’s Table 5-5. Every row has the shape constant − (age coefficient × age) + (height coefficient × height) + (weight coefficient × weight).

Activity row	Women (kcal a day)	Men (kcal a day)
Inactive	584.90 − 7.01 × age + 5.72 × height + 11.71 × weight	753.07 − 10.83 × age + 6.50 × height + 14.10 × weight
Low active	575.77 − 7.01 × age + 6.60 × height + 12.14 × weight	581.47 − 10.83 × age + 8.30 × height + 14.94 × weight
Active	710.25 − 7.01 × age + 6.54 × height + 12.34 × weight	1,004.82 − 10.83 × age + 6.52 × height + 15.91 × weight
Very active	511.83 − 7.01 × age + 9.07 × height + 12.56 × weight	−517.88 − 10.83 × age + 15.61 × height + 19.11 × weight

Choose your row first and write it down, so you can’t swap rows after seeing which answer you like.

How do I calculate TDEE for a female?

Use the women’s column. For a 36-year-old woman who is 167.6 cm and 69.9 kg, the low active row gives 2,278 kcal a day. That is about 9,531 kJ if you read labels in kilojoules, since 1 kcal = 4.184 kJ per the FAO. The sum:

575.77 − (7.01 × 36) + (6.60 × 167.6) + (12.14 × 69.9) = 575.77 − 252.36 + 1,106.16 + 848.59 = 2,278 kcal

Rounded to the nearest 10, that is 2,280.

The same woman in the other rows gets 2,110 kcal (inactive), 2,417 kcal (active) and 2,658 kcal (very active). The man works the same way with the other column. At 45, 180.3 cm and 86.2 kg he gets 2,653, 2,878, 3,064 and 3,457 kcal across the four rows. I checked the active-row sum for him: 1,004.82 − 487.35 + 1,175.56 + 1,371.44 = 3,064 kcal.

If you do this often, put it in a spreadsheet. For the woman’s low active row, with age in A1, height in B1 and weight in C1, the cell reads =575.77-7.01*A1+6.60*B1+12.14*C1.

To skip the arithmetic, use the calorie calculator, which runs the NASEM 2023 equations on your details. It won’t go under 1,200 calories for women or 1,500 for men.

Which activity row should I use?

The one that matches an ordinary week. NASEM’s Table 7-1 gives a typical day for each. Daily living for everyone is about 30 minutes of walking plus about 90 minutes of light to moderate tasks. On top of that:

• Inactive adds nothing.
• Low active adds 60 to 80 minutes of walking at 3 to 4 mph.
• Active adds 30 to 50 minutes of walking, 45 minutes of moderate cycling and 40 minutes of doubles tennis.
• Very active adds 45 minutes of cycling, about 25 minutes of jogging and 60 minutes of tennis.

NASEM says no reliable tool exists to place one person in a category, so treat the table as a guide. When two rows fit, I take the lower one. That is my habit, not NASEM’s advice. The rows sit 139 to 241 kcal apart for the woman above, so the pick is worth real calories. Where your result should land against typical adults is the subject of how many calories per day people need.

Can I use BMR times an activity factor instead?

You can, and plenty of calculators do. Omni’s TDEE calculator is one: the Mifflin–St Jeor equation for resting energy, then a multiplier from 1.2 to 1.9 (the split between the two numbers is laid out in BMR vs TDEE). For a woman it is 10 × weight + 6.25 × height − 5 × age − 161, and for a man the last term is +5. The 1990 paper behind it measured resting energy in 498 healthy adults. For the example woman, 10 × 69.9 + 6.25 × 167.6 − 5 × 36 − 161 = 1,405.5 kcal. Below, the shortcut sits beside the NASEM rows.

Route	Result (kcal a day)
Mifflin × 1.2	1,687
NASEM inactive	2,110
Mifflin × 1.375	1,933
NASEM low active	2,278
Mifflin × 1.55	2,179
NASEM active	2,417

The multipliers land below the NASEM rows at roughly matching labels, by 240 to 420 kcal in this table. That doesn’t prove the shortcut is wrong for you. It does show why two calculators can disagree by a few hundred kcal on the same body. It is also why I prefer the equation whose error NASEM published, a root-mean-square error of 246 kcal for women and 339 kcal for men.

How do I check my TDEE against my own log?

Log what you eat for four weeks, weigh yourself through them, and let the two numbers tell you what you really burn. NASEM puts it as a two-step plan: calculate, then monitor body weight over time and adjust intake.

The arithmetic: say your log averages 2,150 kcal a day over 28 days, and your weekly weight averages fall from 69.9 kg to 69.1 kg. That is 0.8 kg lost, which is 0.8 × 7,700 = 6,160 kcal from your stores over 28 days, or 220 kcal a day. Your TDEE is then 2,150 + 220 = 2,370 kcal, which for someone holding weight is simply their maintenance calories. The equation said 2,278, so the two differ by 92 kcal. That is well inside the equation’s error.

That 7,700 kcal per kg is the old 3,500 kcal-per-pound rule, which Hall and colleagues showed overstates loss over months, so I use it only over a few weeks. It also needs a complete log. NASEM cites a study of 29 people in which getting within 10% of someone’s true average intake took an average of 31 days of records. A missing oil or a skipped weekend turns the sum into noise.

My rule: if your log and the equation disagree by more than the equation’s error and your log is complete, trust the log. If the log has holes, stay with the equation.

These equations cover adults. Pregnancy, breastfeeding, a health condition or a medicine that changes your weight or appetite all change the numbers, so your doctor or midwife sets the target.

The weight check above needs a trend line rather than raw mornings, and Calsa draws your weigh-ins as a smoothed trend, so no spreadsheet is needed.