How much protein do you actually need?
Most protein guidance was built on research that didn't include women your age. This uses Dr. Stacy Sims' published guidance for active women instead.
Why the number is higher than you've been told
The standard recommended daily allowance is roughly 1 gram of protein per kilogram of body weight. As Sims points out, that figure is about enough for someone sedentary — it was never intended as a target for an active woman, and it wasn't built with your stage of life in mind.
Research on women aged 20 to 35 points to 1.6–2.2 g/kg per day. A 2023 review lands on 1.4–2.2 g/kg per day, and adds something most guidance leaves out: it matters how you spread it. Protein distributed evenly across the day, roughly every three to four hours, does more for holding onto lean muscle than the same total eaten mostly at dinner.
Sims notes that older women — particularly through perimenopause and menopause — may need slightly more again, which is why this calculator moves you toward the upper end of the published range rather than inventing a separate number for it.
One more thing worth knowing
Your protein needs aren't flat across the month. Studies show overall daily requirements run higher during the luteal phase — the stretch between ovulation and your period. If you're still cycling, that's a reasonable time to sit at the top of your range rather than the bottom.
Sources. Dr. Stacy Sims, PhD — How Much Protein Is Enough? (April 2025), read the original. Ranges cited within it: Journal of the International Society of Sports Nutrition (2023) and American Journal of Physiology — Endocrinology and Metabolism for luteal-phase requirements.
Educational only. This is a general estimate based on published ranges for healthy, active women — not personalised nutrition advice, and not suitable as guidance if you have kidney disease, are pregnant, or have been given specific protein targets by a clinician or dietitian. Talk to your doctor or a registered dietitian before making significant dietary changes.