Is TDEE different for women?

One term. Mifflin-St Jeor is the same calculation for everyone right up to the final constant, where it adds 5 for men and subtracts 161 for women:

BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5 or − 161

So for two people who are otherwise identical, the gap is a flat 166 kcal at rest. Take a 32-year-old of 175 cm and 70 kg. A man gets 1,639 kcal. A woman gets 1,473. Scale both by a moderate activity factor of 1.55 and the day looks like this:

A 257 kcal difference across the whole day. Real, worth having right, and considerably smaller than the gap most people assume exists.

Mostly body composition. Resting metabolism tracks fat-free mass more closely than it tracks total weight, and at the same height and weight men on average carry more of that mass as muscle and organ tissue. Muscle costs more to maintain at rest than fat does, so the same number on the scale burns slightly differently.

That is also why the correction is a blunt constant rather than something clever. Mifflin-St Jeor is a population equation. It applies the average difference between two large groups, which means it will be wrong in both directions for individuals. A woman carrying more muscle than average is under-estimated by it; a man carrying less is over-estimated.

If you want the resting figure on its own, the BMR Calculator shows every step of the arithmetic, including which constant it applied and why.

No. The multipliers are identical, and that is correct rather than an oversight. The factor describes how much you move relative to your own resting rate, not an absolute amount of energy. A sedentary week is 1.2 of your BMR whoever you are.

Which means the biggest source of error is the same for everyone, and it is not the sex term. Choosing the wrong activity level moves the result by several hundred calories, far more than the 166 kcal the equation adjusts for. It is worth being deliberate about the activity level before worrying about anything else.

Less than the internet claims, and it affects the scale rather than the calculation. When 42 women were weighed twice a week through a full cycle, body weight during menstruation averaged 0.45 kg higher than during the first week of the cycle, and almost all of that increase was extracellular water rather than tissue.

Half a kilogram is measurable, and it is also well inside the ordinary day-to-day noise of a bathroom scale. It is not two or three kilograms, and it is not fat. The practical response is not to eat differently but to compare like with like: the same point in one cycle against the same point in the next, or simply a weekly average that absorbs it. See why your weight changes day to day for how to read the trend rather than the reading.

Energy expenditure does shift a little across the cycle, but the effect is small relative to how imprecise any TDEE estimate already is. It is not a reason to run two different calorie targets.

Pregnancy and breastfeeding both change energy requirements substantially, and no general calculator on this site or any other is the right tool for either. Those targets belong with a doctor or a registered dietitian who knows your history.

Menopause is different in kind. The equation still applies, but body composition often changes over those years, so an estimate that was accurate at 45 may not be at 55. That is not a flaw in the formula so much as a reminder to re-measure. Re-run the numbers, eat near them for three weeks, and let the scale tell you what your real maintenance level is now.

There is no need. Any calculator using Mifflin-St Jeor and asking for your sex is already doing the only adjustment the equation makes. A tool marketed specifically at women is running the same arithmetic behind different styling.

What matters far more is whether the calculator tells you what it did. The TDEE Calculator shows the equation, the constant it applied, the multiplier it used and the arithmetic between them, so you can see exactly which input moved your result rather than trusting a number that arrived without explanation.