Protein calculator for muscle gain

Find your target for building strength — and the ceiling where more protein stops helping.

If you're lifting weights to build muscle, protein isn't optional — but more isn't automatically better past a certain point, and this calculator is built around exactly where that point sits. A 2018 meta-analysis pooling 49 resistance-training studies found that gains in muscle mass and strength from added protein plateaued at roughly 1.6 g/kg of body weight per day. Below that line, more protein tends to help; above it, the pooled data didn't show further benefit. That's why selecting "I lift weights 2+ times a week" below caps your rate at 1.6 g/kg rather than pushing it higher.

The case for supplementing protein around resistance training itself is well established: a meta-analysis of 22 randomized controlled trials with 680 participants found that protein supplementation increased both fat-free mass and leg-press strength during prolonged training — and the effect held in both younger and older lifters, so this isn't a target reserved for people in their twenties. If you're 50+ and started lifting to rebuild strength after time off, the same evidence applies to you.

Timing matters too. Rather than one large protein-heavy meal, sports-nutrition research on protein timing supports spreading your intake across the day in doses roughly every 3–4 hours — which is why this calculator gives you a per-meal target alongside the daily one. Fill in your details below to get both numbers, tuned to how often and how hard you train.

Calculator

How old are you?
What is your sex? (for context only — it doesn't change your numbers)
Whole or decimal numbers both work, e.g. 165 or 74.5
How active are you most weeks?

Your daily protein target

–g / day

About – g per meal, spread across 3–4 meals a day.

  • – large eggs

  • – deck-of-cards chicken portions (85 g each)

  • – g nonfat Greek yogurt

Protein values from USDA FoodData Central and the Canadian Nutrient File. Portion-size guide: MedlinePlus.

Questions about protein and muscle gain

What's the highest protein intake worth aiming for?

A 2018 meta-analysis of 49 resistance-training studies (Morton et al., British Journal of Sports Medicine) found that muscle gains from added protein leveled off at about 1.6 g/kg/day — intakes beyond that didn't produce further gains in the pooled data. That's why "I lift weights 2+ times a week" in the calculator above caps at 1.6 g/kg rather than climbing indefinitely.

Does protein supplementation actually help build muscle when I lift?

Yes, and it's one of the more consistently replicated findings in sports nutrition. A meta-analysis of 22 randomized controlled trials with 680 participants (Cermak et al., 2012, American Journal of Clinical Nutrition) found protein supplementation increased both fat-free mass and leg-press strength during prolonged resistance training, in both younger and older adults.

Do I need to hit my per-meal target exactly, every meal?

Treat it as a practical target, not a rule. Research on protein timing (the ISSN position stand) suggests spreading protein every 3–4 hours across the day, in doses of roughly 0.25 g/kg or 20–40 g, does a better job of maximizing muscle protein synthesis than one large dose. Getting close most meals matters more than hitting the number exactly every time.

I'm over 50 and want to build muscle — is that realistic?

Yes. The Cermak et al. meta-analysis above included older adults specifically and found protein supplementation improved strength and fat-free mass in that group too. Combined with resistance training, higher protein intake is one of the best-supported ways to build or rebuild muscle after 50 — it's not just a younger person's game.

Track your target automatically

CountProtein turns this number into a daily habit — snap a photo of your meal and see how close you are to your target, every day you train.

Track it with the app

Read more: Protein basics · Full calculator + methodology