Creatine Water Intake Calculator

Controlled studies didn't find that it does. A systematic review of trials in athletes exercising in the heat found no evidence that creatine hurts body fluid balance at recommended doses. The creatine and water retention guide goes through the evidence.

We didn't find an official extra-water number. Creatine holds a little water in muscle, and the ISSN position stand reports short-term fluid retention of about 0.5 to 1.0 L during loading. The cushion in this calculator (250 mL on maintenance, 500 mL on loading) is our own practical margin. It isn't a research result.

The ISSN position stand says well-controlled clinical studies show creatine supplementation doesn't increase muscle cramping. If you get cramps, a clinician is a better guide than a calculator.

We don't have a researched figure for water per dose. Follow the directions on your product label, and use the daily target above for the whole day.

We found nothing that makes it necessary. A US gallon is 3.785 L (128 fl oz). In the worked example below, a 180 lb person training 60 minutes a day lands at 3.5 L on maintenance, a bit under a gallon. Your own number depends on your size and training.

The ISSN position stand describes loading as 5 g four times a day (about 0.3 g per kg) for 5 to 7 days, then 3 to 5 g a day to maintain. The calculator adds a larger cushion during loading, 500 mL instead of 250 mL, because of the short-term water retention reported then.

It can. The ISSN position stand says the only consistently reported side effect of creatine is weight gain. In one 2006 trial (Watson et al., 12 active men), body mass rose 0.88 kg after 7 days at 21.6 g a day.

The calculator uses the top of its ranges in hot or humid weather, the same as the main calculator. In one trial of dehydrated, trained men exercising in the heat, a week of creatine didn't compromise hydration or temperature control.