Most people guess their hydration.

They drink when they’re thirsty
or follow generic advice
that ignores what actually matters.

How much you sweat.

This spreadsheet shows
how much fluid and electrolytes you lose per hour
across different activities
based on real-world sweat data.

Gym.
Running.
Combat sports.
Labour work.
Endurance sessions.

You enter your bodyweight once.

And every sweat-loss number
automatically adjusts to your size.

Nothing complex. Just 1 input
No tracking apps.
No overthinking.

Just a clear reference for
how hard your body is bleeding fluid and salt
during real work.

What It Does

• Hourly sweat-loss estimates by activity

• Automatically scales to bodyweight

• Metric-based and easy to read

• Works as a standalone reference or alongside any hydration strategy

• No setup beyond entering your weight

This isn’t a “drink X litres per day” tool.

It’s a rate-based reality check.

Why This Matters

Most hydration mistakes come from not knowing your loss rate.

That leads to:

• chronic underhydration

• low sodium intake

• fatigue and headaches

• cramps

• poor performance

• brain fog during long sessions

If you don’t know what you’re losing,
you can’t replace it properly.

Who This Is For

Anyone who:

• trains hard

• sweats heavily

• works physical jobs

• lives in hot environments

• wants fewer guesses and better outcomes

This index doesn’t replace awareness.
It sharpens it.

Download It Free

Instant access.
No paywall.

Just a clear framework
for understanding your sweat.

Disclaimer

This tool provides estimates, not medical advice. Sweat rates vary based on genetics, heat acclimation, clothing, airflow, and individual physiology. Use real-world feedback and common sense. If you have a medical condition affecting hydration or electrolytes, consult a qualified professional.