BMR Reference for Age 64
Basal metabolic rate at age 64 is not one number — it is a range set by height and weight. This page holds the formula inputs steady at age 64 and sweeps body composition instead: four BMI levels, men at 175 cm and women at 165 cm, each estimated with both Mifflin-St Jeor and Harris-Benedict so the spread between the classic equations is visible at a glance.
The 5 kcal-per-year age term is visible in a single comparison: at 76.6 kg this page lists 1545 kcal, while age 63 lists 1550 — 5 kcal below. The gap between Mifflin-St Jeor and Harris-Benedict on the same row is 46 kcal (3.0%), and the sedentary-to-extra-active span is 1,082 kcal against just 310 kcal of age effect across the whole adult range.
BMR at age 64 by body composition
| BMI | Men (175 cm) | Women (165 cm) | ||||
|---|---|---|---|---|---|---|
| Weight | Mifflin | Harris | Weight | Mifflin | Harris | |
| 20 | 61.3 kg | 1392 kcal | 1386 kcal | 54.5 kg | 1095 kcal | 1186 kcal |
| 25 | 76.6 kg | 1545 kcal | 1591 kcal | 68.1 kg | 1231 kcal | 1311 kcal |
| 30 | 91.9 kg | 1698 kcal | 1796 kcal | 81.7 kg | 1367 kcal | 1437 kcal |
| 35 | 107.2 kg | 1851 kcal | 2001 kcal | 95.3 kg | 1503 kcal | 1563 kcal |
From BMR to daily burn: TDEE at age 64
Multiplying BMR by an activity factor gives total daily energy expenditure. The factors below are the same five levels the main calculator offers, applied to the BMI-25 man from the table (76.6 kg, BMR 1545 kcal):
| Activity level | Factor | TDEE |
|---|---|---|
| Sedentary — little or no exercise | ×1.2 | 1854 kcal/day |
| Lightly active — 1–3 days/week | ×1.375 | 2124 kcal/day |
| Moderately active — 3–5 days/week | ×1.55 | 2395 kcal/day |
| Very active — 6–7 days/week | ×1.725 | 2665 kcal/day |
| Extra active — intense daily training | ×1.9 | 2936 kcal/day |
Get your own figure
Body size matters more than any reference table can capture, so a two-minute personal estimate is usually worth more than a row of averages. Enter your numbers and the box computes the Mifflin-St Jeor result with the same coefficients used across this site:
Frequently asked questions
What is the BMR of a 64-year-old?
It depends on body size as well as age. At age 64, a 175 cm man weighing about 76.6 kg has a Mifflin-St Jeor BMR of roughly 1545 kcal per day, while a 165 cm woman at 68.1 kg lands near 1231 kcal per day. The table above shows how the estimate moves across four common body-composition levels.
Why does BMR fall as age increases?
The Mifflin-St Jeor equation subtracts 5 kcal for every year of age, so between age 20 and age 80 the estimate drops by about 300 kcal per day at the same height and weight. The coefficient is a population average: body composition, not the birthday itself, drives most of the real change.
Mifflin-St Jeor or Harris-Benedict — which should I use?
Mifflin-St Jeor is the default on this site because validation studies found it tracks measured resting energy expenditure more closely for most adults. Harris-Benedict, shown beside it in the table, runs higher for many people — often by 5 to 10 percent — so comparing the two columns is a quick way to see the uncertainty band around any single number.
Nearby ages
Want the full picture — Katch-McArdle from body-fat percentage, the age chart and TDEE in one run? Open the BMRScope calculator or browse every age page.