Creatine dose calculator

What your result means

3 to 5 g a day is your dose, whatever you weigh. It's the amount that keeps muscle full once it's there, and taking more doesn't make you fuller.

The full-by date is the day your stores reach the top on that path. You won't feel anything that day. The extra rep or two on hard sets shows up over the following weeks, as you train on full stores.

The scale band is water that goes into muscle with the creatine. It stops rising once you're full, so a jump in week one isn't fat.

No dose? Under 18, pregnant or breastfeeding, or with kidney disease, the tool stops. That's a question for your doctor, and for anyone under 18, can teens take creatine? has resources instead.

What to do next

1. Test before your first scoop. Push-ups, a dead hang or a plank, twice in the first week. Prove it worked sets your week-eight retest.
2. Weigh in once a week, the same morning, and compare it with what the scale will do.
3. Keep meat or fish in most days if you eat them. Food brings the average American about 0.7 g a day, and foods high in creatine shows what each one adds.
4. Lift two or three days a week, since that's where the extra reps turn into muscle. Creatine for muscle has a 12-week plan.

How it works

The dose. 3 to 5 g of creatine monohydrate a day, printed as a range because that's how the trials and the International Society of Sports Nutrition (ISSN) give it. The trials dosed monohydrate, so labels and these tools count grams of monohydrate. Monohydrate is 87.9% creatine by weight, so a 5 g scoop carries about 4.4 g.

Loading. About 0.3 g per kg a day for 6 days, rounded to the gram and capped at 25 g (the cap is ours, and 0.3 g per kg meets it at about 83 kg, 183 lb). It's split into four servings, each the day's amount divided by four and rounded to the nearest half gram, so no serving is over 10 g. Big single doses are what upset stomachs: one 10 g dose gave 56% of soccer players diarrhea, against 29% on two 5 g doses and 35% on placebo.

The full-by dates. In the 1996 trial that timed both, 20 g a day raised muscle creatine about 20% after 6 days, and 3 g a day got to the same 20% over 28 days. So loading is full at the end of day 6 and 3 to 5 g a day by day 28, counting your first scoop as day 1. 5 g a day may get there a few days sooner, and no trial has timed it.

The curves. Drawn as 1 minus e to the minus t over tau, with tau 2.0 days for loading and 9.35 days for 3 to 5 g, so each curve reaches 95% on its measured day. The shape between the measured days is ours.

Stopping. Stores fall back to where they started about 30 days after the last scoop in the 1996 trial, and in 4 to 6 weeks by the ISSN's count, and never below where they started. The stopping curve uses tau 10 days.

Where your stores start. About 120 mmol per kg of dry muscle on a mixed diet, out of a ceiling near 160, so about three quarters full. Vegetarians and vegans start at 90 to 110 (drawn at 100), and the meat eaters in a 2003 trial started at 130. This sets the gauge, never the dates.

The scale. Ours, built from four trials: loading adds 1% to 3% of body weight by day 7 and then levels off, and 3 to 5 g a day adds 0% to 2% spread over four weeks. What the scale will do has the trials.

Big athletes. The ISSN says larger athletes in hard training may need 5 to 10 g a day to keep stores full. The tool shows that line at 220 lb (100 kg) and up with four or more lifting days a week, a cut that is ours.

No dose for some people. Under 18, the tool prints no dose: the American Academy of Pediatrics advises against performance supplements for teens, and New York bans selling muscle-building supplements to anyone under 18. For pregnancy, breastfeeding or kidney disease there isn't enough research to give a dose, so ask your doctor first.

The dose by weight

Days 6 and 28 from Hultman 1996. 0.3 g per kg, 3 to 5 g and 5 to 10 g from the ISSN position stand (2017). The 25 g cap and the 220 lb line are ours. Some calculators multiply your weight by 0.03 g, which gives 2.4 g at 180 lb. The trials that set the dose used flat amounts, 3 g a day in the slow arm.

Four people, worked out

180 lb, meat a few times a week, lifts 3 days, starts Monday, November 16, no loading. 3 to 5 g a day. Full by Sunday, December 13. Expect the scale to rise up to 3.6 lb over four weeks, then level off. Retest your benchmark on Monday, January 11.

The same person, loading. 24 g a day for 6 days, in four servings of 6 g, then 3 to 5 g. Full by Saturday, November 21. Expect 1.8 lb to 5.4 lb on the scale by day 7, then it stops.

140 lb, vegetarian, cutting, lifts 2 days. 3 to 5 g a day, no loading. Full by Sunday, December 13. The scale may rise up to 2.8 lb in four weeks while you're losing fat, so watch your waist and your weekly average for the first month.

230 lb, lifts 4 days. 3 to 5 g a day. The ISSN says larger athletes in hard training may need 5 to 10 g. Loading is capped at 25 g a day, four servings of about 6 g.