Most women need between 1.2 and 1.6 grams of protein per kilogram of body weight per day, which is the range now recommended in the 2025-2030 Dietary Guidelines for Americans. For a 140-pound woman, that works out to roughly 76 to 102 grams of protein daily. The old baseline of 0.8 grams per kilogram (about 53 grams for that same woman) is still listed as the RDA, but it represents the minimum to avoid deficiency, not the amount needed to thrive.
Your ideal intake depends on how active you are, whether you’re pregnant or breastfeeding, your age, and your goals. Here’s how to find your number.
The Baseline for Moderately Active Women
If you exercise a few times a week and aren’t trying to dramatically change your body composition, 1.2 to 1.6 grams per kilogram of body weight is a solid target. To calculate yours, divide your weight in pounds by 2.2 to get kilograms, then multiply by 1.2 and 1.6 to find your range.
For quick reference:
- 120 lbs (54 kg): 65 to 87 grams per day
- 140 lbs (64 kg): 76 to 102 grams per day
- 160 lbs (73 kg): 87 to 116 grams per day
- 180 lbs (82 kg): 98 to 131 grams per day
The lower end of this range suits someone who walks regularly and does light activity. The higher end fits women who strength train, run, or do other structured exercise several days a week. Protein should make up roughly 10% to 35% of your total daily calories.
Higher Needs for Athletes and Heavy Training
Women who train seriously, whether endurance sports or strength training, need more protein than casual exercisers. Sports nutrition research recommends 1.4 to 1.6 grams per kilogram as a starting point for active women, with intakes up to 2.2 grams per kilogram during periods of heavy training or calorie restriction.
Female endurance athletes may benefit from around 1.9 grams per kilogram on training days, which is actually beyond the upper end of most general athletic guidelines. For a 140-pound runner, that’s about 121 grams. If you’re cutting calories while training (to lose body fat, for example), intakes above 2.0 grams per kilogram help preserve lean muscle mass and support recovery even when energy is limited.
Spacing matters too. Rather than loading all your protein into one or two meals, aim to spread it across the day every three to four hours, with roughly 0.3 grams per kilogram per meal. For most women, that translates to about 20 to 30 grams of protein at each of three or four meals.
How Much Protein Per Meal Actually Counts
Your body can only use so much protein at once for muscle building. Research shows that about 30 grams of protein in a single meal is enough to maximally stimulate muscle repair and growth. Going above 40 grams in one sitting doesn’t appear to offer additional benefit for that process.
For maintaining muscle and strength, especially as you get older, eating one to two meals per day with 30 to 45 grams of protein produces the strongest results. This doesn’t mean protein above 30 grams is “wasted” since it still contributes to your total daily intake, supports satiety, and provides energy. It just means you get more muscle-building benefit from distributing protein across meals rather than packing it all into dinner.
Protein During Pregnancy and Breastfeeding
Protein needs rise gradually throughout pregnancy. In the first trimester, your needs barely change, just an extra 1 to 2 grams per day above your normal intake. By the second trimester, you need about 9 additional grams daily. The third trimester brings the biggest jump, with roughly 28 to 31 extra grams per day on top of your pre-pregnancy baseline.
Some guidelines frame this as a shift from about 0.8 grams per kilogram early in pregnancy to 1.0 grams per kilogram by the end. If you were already eating in the 1.2 to 1.6 range before pregnancy, you’re likely covering the increase, but it’s worth tracking during the third trimester when demands peak.
During breastfeeding, you need about 19 extra grams of protein per day for the first six months if you’re exclusively nursing. After six months, when your baby is also eating solid foods, that drops to around 13 grams extra per day.
Why Protein Needs Increase After 50
Age-related muscle loss begins in your 30s and accelerates after 50. Your muscles become less efficient at using dietary protein to repair and build tissue, which means you need to eat more protein to get the same effect you got from less when you were younger.
The old RDA of 0.8 grams per kilogram is particularly inadequate for older women. Aiming for at least 1.2 grams per kilogram, and ideally closer to 1.6, helps preserve muscle mass and strength. Distributing 30 to 40 grams across each meal appears to be especially important for older adults, since the muscle-building response to smaller protein doses diminishes with age.
Protein for Weight Loss
Higher protein intake supports weight loss in two ways: it keeps you feeling full longer, and it helps preserve muscle while you lose fat. Research from Washington University compared women eating the RDA of 0.8 grams per kilogram during weight loss with women eating 1.2 grams per kilogram. The higher-protein group maintained more muscle tissue during the process.
If you’re actively trying to lose weight, aiming for at least 1.2 grams per kilogram is a reasonable floor. Women who are also exercising regularly during a calorie deficit benefit from going higher, up to 2.0 grams per kilogram, to protect lean mass.
Plant-Based Diets Need a Higher Target
Plant proteins are generally less digestible than animal proteins and contain lower amounts of certain essential amino acids, particularly leucine and lysine, which are critical for muscle repair. This doesn’t make plant protein inferior, but it does mean you need to eat more of it to get the same effect.
Women following a vegetarian or vegan diet should aim for the higher end of protein recommendations: 1.6 to 2.2 grams per kilogram per day. Eating a variety of plant protein sources (legumes, grains, nuts, seeds, soy) throughout the day ensures you get a complete amino acid profile. Relying on a single source, like only rice or only beans, leaves gaps that combining sources can fill.
Can You Eat Too Much Protein?
For healthy women, there’s no established toxic upper limit for protein. However, very high intakes above about 0.9 grams per pound of body weight (roughly 2.0 grams per kilogram), or more than 150 grams daily for a 165-pound woman, can cause dehydration and may stress the kidneys in people who already have kidney conditions. If you have a history of kidney stones or chronic kidney disease, high protein intake can aggravate those problems.
For most women without kidney issues, staying in the 1.2 to 2.0 grams per kilogram range provides the benefits of higher protein intake without meaningful risk. Spreading your intake across meals, drinking adequate water, and getting protein from a mix of whole food sources keeps things simple and safe.