How Much Protein Do I Need a Day? Grams by Goal and Body Weight

Protein advice is a wall of numbers that refuse to agree. A nutrition label cites the RDA. A lifting forum swears by a gram per pound. A podcast quotes grams per kilogram, your training app quotes a percentage of calories, and the tub in your kitchen just says "two scoops." None of them explain why they disagree, so most people either give up and guess, or pick the biggest number on the theory that more must be safer.

Here is the thing the noise hides: every one of those recommendations is the same single multiplication. Your body weight in kilograms, times a factor in grams per kilogram. That is the entire calculation. Every protein argument you have ever heard is an argument about the factor, not the math — and the factor is not a matter of taste. It tracks how hard you train. Get the factor honest and the number falls out in one step; get it from a stranger's Instagram and you inherit a stranger's training week. The two classic mistakes both live here: quoting the RDA of 0.8 g/kg as a target when it is a floor, and hunting for one magic number when the evidence actually gives ranges.

The formula: one multiplication

The whole calculation fits on one line:

• daily protein (g) = weight in kg × goal factor (g/kg)
• weigh yourself in pounds? divide by 2.2 first — the factors are defined per kilogram
• the goal factor: Sedentary 0.8 · General health 1.2 · Endurance 1.4 · Active 1.6 · Build muscle 1.8

That is it. No exponents, no age term, no sex constant, nothing hiding in an appendix. The protein intake calculator runs exactly this: it takes your weight through a kg/lb toggle, converts to kilograms internally, multiplies by the factor your goal sets, and hands back grams per day. On its defaults — 70 kg, Build muscle — it returns 126 g.

Because the formula is one multiplication, two things follow immediately. Change your weight and every figure scales in step: a person half your size needs half your grams at the same goal. Change the goal and only the factor moves, which means the entire spread of protein advice you have ever encountered — from the government minimum to the bodybuilding maximum — is a slider from 0.8 to about 2.2 g/kg, and your only real job is deciding where on that slider your week honestly sits.

The tool accepts weights from 30 to 200 kg. Enter the weight, pick the goal, read the grams.

Quick answer: daily grams by body weight and goal

If you just want the number, find your weight row and your honest goal column. Everything here is the same multiplication, pre-run:

Two notes on reading it. First, these are daily grams of protein, not grams of meat — a portion of chicken or fish weighs far more than the protein it carries, which is why targets that sound modest still take deliberate eating. Second, each cell is a starting point inside a wider evidence range, not a quota to hit to the gram. A 180 lb lifter reading 147 g should treat anything from about 131 to 180 g as defensible territory, for reasons the next sections unpack.

If your weight falls between rows, run your exact number through the calculator rather than interpolating by eye. It is one field and one dropdown.

What the five goals actually mean

The goal names are short, so it is worth spelling out what week each one describes — because picking the flattering goal instead of the honest one is the most common way people end up chasing a target their training does not support.

Sedentary (0.8 g/kg) is a desk job with little deliberate exercise. This is the RDA itself: enough to prevent deficiency, nothing more. General health (1.2) is the generally active life — walks, casual gym visits, recreational sport, nothing structured. Endurance (1.4) is for people whose training is mostly running, cycling, or swimming; endurance work raises protein needs above the sedentary floor but sits somewhat below what strength training demands. Active (1.6) fits someone lifting seriously three or four days a week. Build muscle (1.8) is for lifting hard while actively chasing new muscle — training and eating for gain, not maintenance.

Pick the one that honestly describes your week rather than the one you wish described it. The factor is doing all the work in this formula, so an aspirational goal inflates your target by exactly the gap between your real week and your imagined one. A desk worker running the Build muscle setting gets a number 125% higher than their honest one — 126 g instead of 56 g at 70 kg — and that gap is pure fiction, not ambition.

The honest answer also moves. Start a serious lifting block and you migrate from General health toward Active; hang up the running shoes for a season and you drift back down. Re-pick the goal when your training changes and the target shifts to match. If you lift, tracking your one-rep max over the same period is a decent honesty check: if the training is real enough to move your lifts, it is real enough to justify the higher factor.

The RDA is a floor, not a target

The 0.8 g/kg figure gets quoted everywhere as "how much protein you need," and it is the single most misread number in nutrition. The RDA is the intake set to prevent deficiency in most healthy adults. It answers the question "how little can nearly everyone eat without developing a problem" — a floor. It does not answer "how much supports hard training," which is the question most people typing this into a search bar are actually asking.

That is why the tool's goals climb past 0.8 instead of stopping there. Strength and physique athletes commonly aim for roughly 1.6 to 2.2 g/kg — two to nearly three times the RDA — with endurance athletes somewhat below that band. The five factors are waypoints along this scale: 0.8 is the floor itself, 1.2 and 1.4 serve the active-but-not-lifting middle, and 1.6 and 1.8 sit inside the strength band.

The practical consequence: if you train hard and you have been eating to the RDA because a label told you to, your target is not 10% low. At 70 kg, the gap between the 56 g floor and the 126 g Build muscle default is 70 g a day — more than doubling. This is the mistake that quietly caps people's results for years, because 0.8 g/kg is genuinely enough to be healthy, so nothing feels wrong. The floor keeps you out of deficiency. It was never designed to do anything else.

Worked example: the 70 kg default

Run the calculator's own defaults by hand — a 70 kg (154 lb) person on Build muscle:

• factor for Build muscle: 1.8 g/kg
• 70 × 1.8 = 126 g a day
• evidence range for the goal, 1.6–2.2 g/kg: 70 × 1.6 = 112 g to 70 × 2.2 = 154 g

Now hold the body constant and walk the goals, because this is where the formula's character shows:

• Sedentary: 70 × 0.8 = 56 g
• General health: 70 × 1.2 = 84 g
• Endurance: 70 × 1.4 = 98 g
• Active: 70 × 1.6 = 112 g
• Build muscle: 70 × 1.8 = 126 g

Same scale, same person, and the daily target more than doubles from bottom to top. Nothing about the body changed — only the claim about how it trains. That is worth sitting with, because it explains why protein advice sounds so contradictory: two sources quoting 56 g and 126 g for the same person can both be applying the same formula correctly, just with different assumptions about the week. When you read a protein recommendation anywhere, the useful question is never "is this number right?" It is "whose training week is this factor describing, and is it mine?"

Notice also how the goals overlap once ranges enter. Active's band runs 1.4–1.8 g/kg (98–126 g at 70 kg) and Build muscle's runs 1.6–2.2 (112–154 g). The 112–126 g stretch belongs to both. If you honestly straddle two goals, that shared territory is exactly where you should land, and fretting over which label you picked is wasted effort.

Worked example: a 180 lb lifter

Most people in the US weigh themselves in pounds, so here is the full arithmetic including the conversion. A 180 lb lifter training hard for muscle:

• convert: 180 ÷ 2.2 = 81.8 kg
• multiply: 81.8 × 1.8 = 147 g a day
• range, 1.6–2.2 g/kg: 81.8 × 1.6 = 131 g to 81.8 × 2.2 = 180 g
• per meal over four meals: 147 ÷ 4 ≈ 37 g

The range's top end deserves a second look. The famous gym rule of "one gram per pound of body weight" is, converted, 2.2 g/kg — which is precisely the ceiling of the evidence band, not its middle. For our lifter that is 180 g against the tool's 147 g default. So the per-pound rule is not wrong, exactly; it is maximal. It plants you at the top of the range where the last increments buy the least, and it costs the most effort and food to sustain. The 1.8 g/kg default (about 0.82 g per pound) lands mid-band: high enough to support building muscle, low enough to actually hit every day for months.

That last part matters more than the arithmetic. A target you hit six days out of seven beats a ceiling you hit twice a week, and the gap between 147 and 180 g is roughly an extra chicken breast and a shake, every single day. If eating is easy for you and training is heavy, drift up inside the band. If you are forever falling short, the bottom of the band at 131 g is still squarely inside the evidence. The band is the answer; the single number is where you start inside it.

Current weight or goal weight?

One question the formula cannot settle on its own: which weight goes into it when the scale is moving? The calculator takes whatever you enter, so the choice is yours — and the honest default is the weight you have today. The factor describes the body doing this week's training, and that body is your current one. If you are within a few kilograms of your goal in either direction, the difference between the two inputs is noise inside the evidence range anyway; use today's weight and move on.

The exception is a large gap. Body fat does not call for protein the way muscle does, so when current and goal weight sit far apart, running the math on your full current weight overshoots. Take someone at 100 kg working toward 80 kg on the Build muscle setting: current weight returns 100 × 1.8 = 180 g — the same figure as the table's 220 lb row — while goal weight returns 80 × 1.8 = 144 g. The 180 g target is not harmful, just needlessly hard: 36 extra grams a day, every day, aimed at tissue that is not asking for it. Entering the goal weight, or anything between the two, gives a target you can actually sustain while the weight comes down.

Either way, the input goes stale as you change — which is the real answer to the question. Re-run the calculator as the scale moves and the current-versus-goal debate resolves itself a kilogram at a time.

Spread it across the day

The daily total is only half the instruction. The research on muscle protein synthesis points to dividing your intake across roughly three or four meals of about 20–40 g each, which supports muscle better than loading nearly all of it into one large serving. A day of coffee, a sandwich, and one heroic 120 g dinner technically hits the total and still leaves most of the day's opportunity on the table.

So once you have a daily target, divide it by your meals to get a per-meal goal. The default 126 g over four meals is a little over 30 g a meal — squarely in the window. The 180 lb lifter's 147 g over four is about 37 g, also inside. Run it over three meals instead and the picture tightens: 126 ÷ 3 = 42 g, just past the window's top, and 147 ÷ 3 is 49 g. Neither is a catastrophe, but it shows why four protein-bearing meals is the comfortable shape for higher targets while three works fine for moderate ones — a 98 g endurance target over three meals is roughly 33 g each, no fourth meal required.

The practical version: stop treating breakfast as a protein-free zone. If dinner is your only serious protein meal, you are running the pile-up pattern on the left of the figure. Moving some of it earlier costs nothing — the total stays identical, the distribution does the extra work.

Hitting the target with real food

A grams-per-day number is abstract until it is on a plate. The dependable sources are lean meat, fish, eggs, dairy, legumes, tofu, and protein powders. Animal sources are protein-dense and easy to portion, which is why they anchor most high-protein diets. Legumes and tofu carry a plant-based diet to the same targets with a bit more planning and volume. Powders are the convenience option, not the foundation — a top-up for the days food falls short.

The honest sequencing is food first, powder last. Most people reach a moderate target through food alone, and building meals around whole sources brings everything else those foods carry along for free. The pattern that works is boring: make each of your three or four meals contain one deliberate protein anchor — eggs or yogurt in the morning, meat, fish, tofu, or legumes at the others — then check the day's total against your target. If a real gap persists after that, a shake closes it in thirty seconds.

Treat the target as something to refine over weeks, not a quota to chase to the gram. Protein intake is a daily average game; one low Tuesday does not undo anything, and one enormous Saturday does not bank ahead. Aim to be near the number most days, adjust the anchors when you are consistently short, and re-run the calculator when your weight or training changes enough for the inputs to have moved.

The kidney question

Ask about eating more protein anywhere public and someone will warn you about your kidneys. The concern sounds plausible — kidneys process protein's nitrogen — but for healthy people it does not hold up: there is no good evidence that higher protein intake causes kidney damage in people with healthy kidneys. The intakes in this guide's ranges, up to the 2.2 g/kg athletic ceiling, are territory strength athletes have occupied for decades without the damage the myth predicts.

The exception is real, though. People with existing kidney disease may need to limit protein and should follow their own medical advice — their situation inverts the usual logic, and no general-purpose calculator overrides a nephrologist. That is also the honest place to say what this whole guide is: general, evidence-based guidance for healthy adults, the same framing the calculator itself carries with its medical disclaimer. If you have a diagnosed condition, are pregnant, or are managing anything under a clinician's care, take the number to your doctor or a registered dietitian before acting on it.

Protein needs a calorie budget behind it

A protein target never operates alone. The grams from this calculator land inside a day of total eating, and the size of that day is set by your energy needs — which protein math says nothing about. It is entirely possible to nail 147 g a day while eating so far under or over your energy needs that the results disappoint anyway.

That budget comes from two sibling numbers. Your BMR is what your body burns at complete rest — the floor of your energy needs, the same way the RDA is the floor of protein. Your TDEE layers your activity on top of that floor to give the number you can actually plan a day's eating around. The workflow that makes all three tools click: what your BMR means explains the floor, TDEE turns it into a budget, and the protein target decides how much of that budget is spoken for by protein before carbohydrates and fat divide the rest.

Run them in that order and the numbers stop being trivia and start being a plan: a calorie budget sized to your goal, with a protein line item inside it sized to your training.

Common mistakes to avoid

• Treating the RDA as a target. 0.8 g/kg prevents deficiency; it does not support hard training. If you train, your factor starts at 1.4–1.8, not 0.8.
• Picking the aspirational goal. The factor mirrors your actual week. Choosing Build muscle for a desk-and-sofa week inflates the target by fiction, not ambition.
• Forgetting the unit conversion. The factors are per kilogram. Multiplying 180 pounds by 1.8 gives 324 g — a nonsense number. Divide by 2.2 first: 81.8 × 1.8 = 147 g.
• Chasing the single number instead of the range. 126 g at 70 kg is the middle of a 112–154 g band. Anywhere in the band is defensible; day-to-day consistency beats gram-level precision.
• Loading everything into dinner. Three or four meals of 20–40 g support muscle protein synthesis better than one giant serving of the same total.
• Starting with powder instead of food. Meat, fish, eggs, dairy, legumes, and tofu first. The shake is for the gap that remains, if one does.
• Never re-running the number. Weight changes and training changes both move the target. The formula is one multiplication — it costs nothing to redo.

Strip the noise away and the question has a short answer: your weight in kilograms, times a factor between 0.8 and 1.8 that honestly matches your training, read as the middle of a range, split into three or four meals. Everything else — the forum rules, the per-pound slogans, the label percentages — is the same multiplication wearing different clothes.