How to Calculate Your Maintenance Calories

TL;DR: Your maintenance calories (TDEE) = BMR × activity multiplier. Use Mifflin-St Jeor for BMR. Multiply by 1.2-1.9 based on activity level. Then eat at that level for 2 weeks and track your weight. If you're gaining, reduce 100-150 kcal. If you're losing, add 100-150 kcal. Adjust until your weight is stable. That's your true maintenance.

Every diet, cut, and bulk starts with knowing your maintenance calories. Get this number right and everything else becomes straightforward math. Get it wrong and you'll be spinning your wheels wondering why the plan isn't working.

The problem: every TDEE formula is an estimate. Population-level equations can't account for your individual metabolism, NEAT (non-exercise activity thermogenesis), muscle mass, or the variability in your day-to-day movement. The good news is there's a reliable way to calibrate the formula output to your actual body.

Step 1: Calculate BMR with Mifflin-St Jeor

Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest, just to keep organs running.

For men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5

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

Example (180 lb, 5'11", 30-year-old man):

Weight: 180 lbs = 81.6 kg
Height: 5'11" = 180.3 cm
BMR = (10 × 81.6) + (6.25 × 180.3) − (5 × 30) + 5
BMR = 816 + 1,127 − 150 + 5 = 1,798 kcal

Use Mifflin-St Jeor rather than the older Harris-Benedict equation. When Frankenfield et al. (2005) reviewed the predictive equations against measured resting metabolic rate, Mifflin-St Jeor landed within 10% of the measured value more often than any other formula tested, in roughly 4 out of 5 non-obese adults. It's the best starting guess available without a metabolic cart.

Note the flip side of that result. Even the best equation misses by more than 10% for about one person in five. If you're that person, no amount of recalculating fixes it. Step 4 does.

Step 2: Multiply by Your Activity Multiplier

| Activity Level | Description | Multiplier | |---------------|-------------|-----------| | Sedentary | Desk job, little to no exercise | 1.2 | | Lightly active | Light exercise 1-3 days/week | 1.375 | | Moderately active | Moderate exercise 3-5 days/week | 1.55 | | Very active | Hard exercise 6-7 days/week | 1.725 | | Extra active | Physical job + hard daily training | 1.9 |

Continuing the example: Moderately active (trains 4x/week): 1,798 × 1.55 = 2,787 kcal

This is your estimated TDEE starting point.

Step 3: The Problem with Multipliers

Activity multipliers are population averages. They don't know that you're a fidgeter (more NEAT), or that your job involves walking a warehouse floor (more NEAT than "sedentary" implies), or that your training is genuinely intense vs. going through the motions.

Levine (2004) put the between-person spread in NEAT at up to 2,000 kcal/day. Two people with the same job title and the same training program can have dramatically different daily burns because one constantly shifts, paces and gestures while the other sits still.

That's why formula estimates commonly land 300-500 kcal off the mark. The formula isn't broken. It just has no way to see your movement. I've written more on where that error comes from in why your TDEE calculator is wrong by 300+ calories.

Step 4: Real-World Calibration (2-Week Test)

This is the most reliable way to find your actual maintenance:

Set your intake at the formula-estimated TDEE
Weigh yourself daily for 14 days, first thing in the morning
Calculate the 7-day moving average (average of 7 consecutive days)
Compare week 1 average to week 2 average

Interpreting results:

Weight stable (±0.5 lb/week) → You're at maintenance
Gaining 0.5+ lb/week → Reduce by 100-150 kcal and retest
Losing 0.5+ lb/week → Add 100-150 kcal and retest

Repeat in 2-week blocks until weight is stable. This is now your calibrated maintenance.

Daily weigh-ins feel excessive to people who've been told to weigh once a week. They aren't. A single weekly reading is one noisy data point, and water shifts of 2-4 lbs can swamp the signal entirely. Seven readings averaged together cancel most of that out, which is the whole argument for weighing yourself every day and reading the trend.

When the Two-Week Test Gives You a Bad Answer

The calibration is only as good as the data going into it. A few things reliably corrupt it:

You started creatine. Creatine pulls water into muscle and typically adds 2-4 lbs on the scale in the first couple of weeks. That looks like a surplus. It isn't. Start the test before you start creatine, or wait three weeks after.

You're comparing across a menstrual cycle. Fluid retention swings across the cycle can easily exceed the signal you're looking for. Compare the same phase to the same phase, which in practice means running a four-week test and comparing week 1 to week 5.

Your intake wasn't actually consistent. Underreporting is the quiet killer here. Lichtman et al. (1992) measured self-reported intake against doubly labeled water in people who believed they were diet resistant, and found they were under-reporting by around 47%. If your log says 2,800 and the scale says surplus, the log is usually the thing that's wrong.

You used your watch's "calories out" number as TDEE. Don't. Consumer wearables estimate energy expenditure with error rates that make them useless as a calorie target, which I covered in detail on Apple Watch calorie burn accuracy. Use the watch for heart rate and workout logging. Get your TDEE from the scale.

Step 5: Recalibrate Over Time

Maintenance calories change as your weight, muscle mass, and activity level change. Recalculate every 10-15 lbs of weight change, or any time your training volume shifts significantly.

Common triggers to recalculate:

Lost 10+ lbs (lighter body = lower TDEE)
Gained significant muscle
Started or stopped a physically demanding job
Significantly changed training frequency/volume

There's one more trigger worth naming. After a meaningful weight loss, your maintenance can sit below what the formula predicts for your new bodyweight. Sumithran et al. (2011) followed subjects a full year after a 10-week diet and found the hormonal changes driving hunger and lower energy expenditure were still present at 12 months. Your post-diet maintenance is an empirical question, not a formula output. Run the two-week test again rather than assuming.

Common Mistakes to Avoid

Using online calculators without validating: They give you a starting point, not the answer. The 2-week calibration step is non-negotiable for accuracy.

Picking the wrong activity multiplier: Most people overestimate their activity level. When in doubt, pick the lower option and adjust up.

Weighing once per week: Daily weigh-ins with a moving average give you a much cleaner trend signal. Single weigh-ins are too noisy from water retention.

Not accounting for consistency: The 2-week test only works if you're eating the same number of calories each day. Wildly variable intake makes the signal impossible to read.

Treating one calibration as permanent: A number that was right in January is not automatically right in June. If progress stalls, that's the first thing to re-check, and it's the first stop in how to break a weight loss plateau.

Bottom Line

Mifflin-St Jeor × activity multiplier gives you a solid starting estimate. The two-week calibration converts that estimate into a number that actually reflects your metabolism. Once you have that calibrated maintenance, setting a deficit or surplus becomes precise rather than guesswork.

The catch is that doing this properly means re-running the test every time your body or your training changes, and most people quit after the first round. Use our Macro Calculator for the starting estimate, then download Protokl if you'd rather have the recalibration happen on its own. It reads your actual weight trend against your logged intake and moves your maintenance number for you, which is the part of this process nobody keeps up with by hand.