The sweat sodium calculator your body already has the answer to.
Tell it what you did, how long, and how salty you sweat. It gives you your estimated hourly Na, K, and Mg target — and the cheap real-ingredient mix that hits it. Nothing to install. No signup wall.
Get your number →What it calculates
Three numbers you'd otherwise pay a sweat lab $130–$200 to hand back to you:
- Sodium (Na) — the number that actually matters. Ranges from ~400 mg/hr for a light rider to 2,500+ mg/hr for a heavy salt sweater in heat.
- Potassium (K) — proportional to sodium loss (about 29%). Most sports drinks skip it.
- Magnesium (Mg) — 300 mg supports muscle function on long efforts. Small amount, big signal.
Then it tells you the ounces of water to sip across the session and the real ingredients at cost that hit the target — about $1.50–$2 a session instead of $6.50 for a premixed tab.
Two modes — quick and precise
Both give the same output — your target and your recipe. The precise mode is what a sweat lab actually measures; it's just your scale doing the reading.
Why not just buy a sports drink?
Because your sodium loss isn't the average, and pre-mixed tabs are formulated for the average. If you're a light sweater, most tabs give you too much. If you're a heavy sweater in heat, they give you a third of what you need — which is why you cramped last time. A calculated number, hit with real ingredients, is your number.