Most women need between 1.2 and 1.6 grams of protein per kilogram of body weight per day. For a 140-pound woman, that works out to roughly 76 to 102 grams daily. This range, recommended in the 2025-2030 Dietary Guidelines for Americans, is significantly higher than the older minimum of 0.8 grams per kilogram (about 53 grams for that same woman) that many people still reference.
The right number for you depends on your activity level, age, and whether you’re pregnant or breastfeeding. Here’s how to find your target.
The Baseline: What Most Women Need
For years, the standard recommendation was 0.8 grams of protein per kilogram of body weight, or 0.36 grams per pound. That number was designed to prevent deficiency in sedentary adults, not to optimize health. The updated Dietary Guidelines now recommend 1.2 to 1.6 grams per kilogram, reflecting a growing body of evidence that higher protein intake supports muscle maintenance, satiety, and metabolic health across the lifespan.
To calculate your personal range, divide your weight in pounds by 2.2 to get kilograms, then multiply by 1.2 (lower end) and 1.6 (upper end). A few examples:
- 130 pounds (59 kg): 71 to 94 grams per day
- 150 pounds (68 kg): 82 to 109 grams per day
- 170 pounds (77 kg): 92 to 123 grams per day
The federal guidelines also frame protein as 10 to 35 percent of total daily calories for adults. On a 2,000-calorie diet, that’s 50 to 175 grams, a very wide range. The per-kilogram calculation gives you a more personalized number.
How Exercise Changes the Target
If you work out regularly, your protein needs go up. Women who exercise consistently, whether that’s running, cycling, swimming, or group fitness classes, do well with about 1.1 to 1.5 grams per kilogram. If you lift weights or are training for an endurance event like a marathon, the recommendation climbs to 1.2 to 1.7 grams per kilogram.
For a 150-pound woman who strength trains three or four times a week, that translates to roughly 82 to 116 grams of protein a day. The increase over baseline needs isn’t as dramatic as supplement marketing might suggest. A Harvard nutrition expert puts it this way: if you’re doing intense workouts and trying to build muscle, you might need about 50 percent more protein than the old sedentary baseline, not double or triple.
Protein Needs After 50 and During Menopause
Muscle loss accelerates with age, and the hormonal shifts of menopause make it harder for your body to build and maintain lean tissue. An international expert group on aging (PROT-AGE) recommends that older adults consume 1.0 to 1.2 grams of protein per kilogram daily just to maintain muscle mass. That aligns well with the updated dietary guidelines and means a 150-pound postmenopausal woman should aim for at least 68 to 82 grams a day as a floor, not a ceiling.
There’s an important nuance here: older bodies are less efficient at using protein. Research shows that older adults need roughly double the amount of protein in a single meal to trigger the same muscle-building response that younger adults get. While 20 grams of protein at a meal may be enough to maximize muscle repair in a 25-year-old, women over 50 likely need closer to 30 to 40 grams per meal to get the same benefit. Simply meeting a daily total isn’t enough if most of that protein is loaded into one meal.
Higher protein intake alone won’t prevent age-related muscle loss, though. The research is clear that protein above the baseline improves lean mass and strength primarily when combined with resistance training. The two work together.
Protein During Pregnancy and Breastfeeding
Protein requirements increase gradually throughout pregnancy. In the first trimester, the increase is negligible, just an extra gram or so per day. By the second trimester, you need about 9 additional grams daily. The third trimester brings the biggest jump: an extra 28 to 31 grams per day on top of your normal needs.
For a woman who normally needs about 80 grams of protein, that means roughly 108 to 111 grams daily in late pregnancy. Some guidelines express this as a gradual shift from 0.8 grams per kilogram early on to about 1.0 gram per kilogram by the end of pregnancy.
Breastfeeding demands remain high. During the first six months of exclusive breastfeeding, you need about 19 extra grams of protein per day. After six months, when babies start eating solid foods and nursing less, the extra requirement drops to around 13 grams. Some guidelines set the total recommended intake for breastfeeding women at 1.2 grams per kilogram of body weight.
Protein for Weight Loss
When you’re eating fewer calories than you burn, your body doesn’t just pull energy from fat. It also breaks down muscle tissue. Eating more protein during a calorie deficit helps preserve lean mass, which matters both for how you look and for keeping your metabolism from slowing down.
Research shows that lean mass and strength can be better preserved when protein intake is above the old 0.8 g/kg baseline during weight loss. Aiming for the higher end of the 1.2 to 1.6 g/kg range makes sense when you’re in a deficit. For a 160-pound woman cutting calories, that means targeting roughly 100 to 116 grams of protein daily, even if total food intake is lower than usual. Protein is the last macronutrient you want to cut back on when losing weight.
How to Spread Protein Across the Day
Your body can only use so much protein at once to repair and build muscle. Studies show that about 30 grams of protein in a single meal is enough to maximize muscle protein synthesis in most adults, and eating more than that in one sitting doesn’t meaningfully increase the muscle-building response. For older women, that threshold is closer to 40 grams.
This means eating 90 grams of protein is more effective when split across three meals of 30 grams than when you eat 10 grams at breakfast, 15 at lunch, and 65 at dinner. That lopsided pattern is surprisingly common. Many women eat very little protein at breakfast, a moderate amount at lunch, and the bulk at dinner.
A practical approach: aim for at least 25 to 35 grams of protein at each main meal. A palm-sized portion of chicken, fish, or tofu gets you about 25 to 30 grams. Two eggs plus Greek yogurt at breakfast can hit 25 grams. If you snack, choosing protein-rich options like cottage cheese, edamame, or a handful of nuts helps fill gaps.
Plant-Based Protein Considerations
If you eat mostly or entirely plant-based, you can absolutely meet your protein needs, but it takes a bit more planning. Plant proteins tend to be lower in certain amino acids (especially leucine, which is a key trigger for muscle repair) and are generally less digestible than animal proteins. This doesn’t mean plant protein is inferior, but it does mean you may need a slightly higher total intake to get the same muscle-building effect.
Variety helps. Combining different plant sources throughout the day, like beans with grains, tofu with lentils, or nuts with seeds, covers the full spectrum of amino acids. You don’t need to combine them at every meal, just over the course of the day. Soy-based foods (tofu, tempeh, edamame) are the closest plant equivalents to animal protein in terms of amino acid profile and are a reliable staple for women aiming to hit higher targets.