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Protein Calculator

Get a general idea of how many grams of protein a day suit your body weight and how active you are.

Level: Grade 6

Printable worksheet

Protein Calculator

Inputs
Units

Optional. Splits your daily range evenly across your meals.

Result

General protein range

82–98 g per day

At about 81.6 kg and regularly active, a general range is roughly 82–98 g per day. It's a guide, not a personal plan.

Low end
82 g/day
High end
98 g/day
Adult reference intake (0.8 g/kg)
65 g/dayA general amount set for healthy adults as a group. It isn't a personal goal.
Per meal
27–33 g per meal

See the step-by-step solution ↓

Step-by-step solution

  1. Change your weight to kilograms, because protein advice is given per kilogram (1 lb = 0.45359237 kg exactly)

    180 lb×0.453592=81.647 kg

  2. Find the low end: multiply your weight by 1 grams for each kilogram, the bottom of the regularly active band

    81.647 kg×1 g/kg=81.6 g

  3. Find the high end: multiply your weight by 1.2 grams for each kilogram, the top of the band

    81.647 kg×1.2 g/kg=98 g

  4. Round both ends to the nearest gram to get your daily range

    82–98 g per day

  5. For comparison, work out the general adult reference amount of 0.8 grams for each kilogram

    81.647×0.8=65.3 g

  6. Divide each end by 3 meals to see roughly how much to eat at each one

    81.63 to 983=27–33 g per meal

Test yourself

20 quick questions built from this calculator's formula: work out results, predict what happens when an input changes, and work backward from an answer. Every answer comes with the working.

Please note: This calculator gives a general screening estimate, not a diagnosis. Talk to a qualified healthcare professional about your individual health.

What this calculator does

Find a general range for how many grams of protein to eat each day, based on your weight and activity. Protein advice is usually given in grams for each kilogram of body weight per day, written g/kg. For healthy adults, the widely used reference amount is 0.8 g/kg. It's meant to cover the needs of nearly all healthy adults who aren't especially active. People who exercise regularly, especially with endurance or strength training, are often advised to aim higher.

The calculator multiplies your weight by the low and high ends of a general g/kg range for the activity level you pick. It also shows the 0.8 g/kg reference next to it, so you can compare. These are general ranges, not a personal plan or medical advice. Protein needs can be quite different with kidney disease, pregnancy, older age, illness or after a medical procedure. So check with a doctor or registered dietitian before making big changes.

Where it's used

Why this math matters outside the classroom:

  • Grams per kilogram. At 0.8 g per kg, a 70 kg adult's reference intake is 0.8 × 70, which is 56 g of protein a day.
  • Pounds to kilograms. A 165 lb person converts to about 74.8 kg before multiplying by a grams-per-kilogram figure.
  • Meal planning. Home cooks split a daily protein figure across three meals to plan portions for the week ahead.
  • Reading labels. Shoppers compare the protein grams on a food label with their daily figure to see how much one serving covers.
  • Training seasons. Athletes recheck their range when their weight or training load changes between seasons.

Grade level and standards: Grade 6; Common Core State Standards for Mathematics 6.RP.A.3.b, 6.RP.A.3.d. © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved.

How to use it

  1. Choose pounds or kilograms and enter your current body weight.
  2. Pick the activity level that matches a typical week for you.
  3. If you like, enter how many meals you usually eat to see the range for each meal.
  4. Read your daily range in grams and compare it with the adult reference amount.

What the inputs mean

Weight
Use your current weight. For people carrying a lot of extra weight, some professionals work from a reference or adjusted weight instead. This calculator doesn't do that.
Activity level
Mostly inactive starts at the 0.8 g/kg reference. Regularly active covers people who exercise a few times a week. The endurance and strength bands follow ranges often cited for people who train steadily. They aren't meant for the occasional workout.
Meals per day
Spreading protein across several meals is a common, practical approach. Leave this blank if you only want the daily total.

Formula and method

Low end (g/day) = body weight (kg) × low g/kg
High end (g/day) = body weight (kg) × high g/kg
Reference intake (g/day) = body weight (kg) × 0.8
Weight (kg) = weight (lb) × 0.45359237

In the formulas, g/day is grams of protein per day, kg is kilograms and lb is pounds. The g/kg number is grams of protein for each kilogram you weigh. The bands are 0.8–1.0 g/kg (mostly inactive), 1.0–1.2 g/kg (regularly active), 1.2–1.6 g/kg (endurance training) and 1.6–2.0 g/kg (strength training). They're broad, rounded figures. They were chosen to sit inside ranges often cited in nutrition guidance and sports-nutrition research.

Pounds are changed to kilograms with the exact international definition. The per-meal figure divides both ends of the daily range by the number of meals.

Worked example

A person weighing 180 lb exercises a few times a week (regularly active) and eats three meals a day.

  1. Change pounds to kilograms: 180 × 0.45359237 = 81.647 kg.
  2. Low end: 81.647 × 1.0 = 81.6 g. High end: 81.647 × 1.2 = 98.0 g.
  3. Rounded, that's 82–98 g per day. The 0.8 g/kg reference would be 65.3 g.
  4. Split across three meals: 27–33 g per meal.

Result: The general range is 82–98 g per day, or about 27–33 g per meal.

Understanding the result

The range is a band, not an exact target. Landing anywhere inside it on a typical day fits the general guidance it's based on.

The 0.8 g/kg reference is set to meet the needs of most healthy adults. It's not a maximum. Active people often go somewhat above it. Very high amounts, though, give little extra benefit for most people.

To see how protein fits into your total calories, along with carbs and fat, try the macro calculator.

Assumptions and limitations

  • You're a healthy adult who isn't pregnant or breastfeeding.
  • Body weight means your current total weight, not your lean mass or an adjusted weight.
  • You choose your own activity band, and the bands are general. Results are rounded to the nearest gram on screen.
  • These ranges don't account for kidney or liver disease, diabetes, illness, injury, pregnancy, older age or other conditions that change protein needs.
  • If you carry a high share of body fat, using total body weight can overstate your needs.
  • It doesn't consider protein quality or timing. It isn't meant for children or teens.

Frequently asked questions

Is 0.8 g/kg enough protein?

For most healthy adults who aren't very active, 0.8 g/kg is the reference amount expected to meet their needs. Many people who train regularly aim higher. A registered dietitian can help you decide what suits you.

Can I eat more protein than the top of the range?

Healthy adults often do without obvious harm. But there's little evidence of extra benefit for most people beyond about 2 g/kg. Anyone with kidney problems should get medical advice before eating more protein.

Should I use grams per pound instead?

You can switch between them: divide a g/kg figure by about 2.2 to get grams per pound. So 1.6 g/kg is about 0.73 g per pound. The calculator does this for you when you enter your weight in pounds.

Do older adults need more protein?

Some expert groups suggest older adults may benefit from a bit more than 0.8 g/kg, often around 1.0–1.2 g/kg, to help keep muscle. Needs depend a lot on your health, so talk this over with a healthcare professional.

How this calculator is checked

Method: Body weight (kg) × g/kg band. 0.8 g/kg is the adult reference intake (RDA); higher bands are rounded ranges within those commonly cited for regular exercisers (about 1.2–2.0 g/kg). The calculation is covered by automated tests with known reference values and edge cases. Last updated 2026-10-18. Found a problem? Tell us.

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