Hydration Check: A 2-Second Self-Assessment

Track urine color and void frequency with a validated clinical scale — no gimmick camera, just honest science.

Your Urine Tells You What Your Water Bottle Can't

Drinking water is step one. Knowing if you're actually hydrated is step two. Concentrated urine is where kidney stones form, and color is the simplest validated indicator.

2 Seconds, Not 2 Minutes

Tap a color. Done. No photos, no camera alignment, no waiting for AI. A habit you'll actually keep.

Clinically Validated

The Armstrong scale (1994) is used in sports medicine, military, and clinical research. Not a gimmick — real science.

Trends Over Time

A single check means little. A week of morning voids tells your real hydration story. See patterns you'd miss otherwise.

The Armstrong Scale: 6 Levels of Clarity

Each level corresponds to a validated hydration status. Tap the color that matches, and Hydration Check does the rest.

1
Pale Straw
Well Hydrated
2
Light Yellow
Hydrated
3
Yellow
Fair
4
Dark Yellow
Mildly Dehydrated
5
Amber
Dehydrated
6
Dark Amber
Severely Dehydrated

Why We Don't Use a Camera

Some apps promise to read your urine color through your phone camera. The evidence shows this approach is unreliable. Lighting, toilet bowl color, camera sensor variation, and screen calibration all introduce errors. A 2-second self-assessment against a standardized chart is more accurate in real-world bathroom conditions.

We chose science over gimmicks.

The Science Behind Urine Color

Learn why urine color is the most practical daily hydration indicator and how the Armstrong scale was validated against laboratory measurements.

Read the full science behind Hydration Check
6
Color Levels
1994
Validated Scale
2 sec
Per Check
Free
To Start

More Ways to Stay Safe

Frequently Asked Questions

What is the Armstrong scale?
The Armstrong urine color scale is a validated clinical tool published in 1994 by Dr. Lawrence Armstrong. It uses 6 color levels from pale straw (well hydrated) to dark amber/brown (severely dehydrated). It has been validated against urine specific gravity and osmolality as a reliable indicator of hydration status.
Why not use a camera to read urine color?
We specifically chose NOT to use phone cameras for urine color assessment. Research shows that lighting conditions, toilet bowl color, phone camera sensors, and screen calibration introduce too much variability. A self-assessment against a standardized color chart is actually more reliable than an automated camera reading in real-world bathroom conditions.
Why is morning void most important?
Your first void of the day reflects your overnight hydration status without the influence of recent fluid intake. It is considered the gold standard indicator in hydration research. If your morning void is consistently dark (levels 4-6), you are likely chronically under-hydrated regardless of what you drink during the day.
How often should I check?
For kidney stone prevention, checking your morning void daily is the most valuable habit. Beyond that, checking 2-3 times throughout the day gives a complete picture. The app makes each check take about 2 seconds — tap the color, done.
Can medications affect urine color?
Yes. Certain medications and supplements (B vitamins, some antibiotics, beet consumption) can alter urine color independently of hydration status. The app lets you note these factors so your trend analysis stays accurate.
How does this connect to my oxalate tracking?
Hydration Check feeds into your overall OxalateGuard dashboard. When you log concentrated urine alongside a high-oxalate meal, the app can warn you that your kidneys are processing oxalate without adequate dilution — a key risk factor for stone formation.

Two seconds to know your hydration status.