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//// Health · Hydration

Water Intake Calculator

Find your daily hydration target in oz, liters, and cups — adjusted for your weight, workout duration, and climate.

Where this fits

❤️ HealthHouseholds

This tool sits in the health domain and connects best with the next tools in that decision lane.

Healthy BMI18.5 – 24.9
Daily Calories2,000 – 2,500
Sleep Cycle90 min

Daily Water Target

97oz

2.87L12.1 cups12.1 glasses (8oz)
76%

of 1 gallon

(128 oz)

lbs
30 min
0 min306090120 min
min

Intake Breakdown

Baseline (weight-based)
85 oz170 lbs × 0.5
Exercise (30 min)
+12 oz1.0 × 12 oz
Climate
+0 oztemperate
Total97 oz

Ounces

97oz

Liters

2.87L

Cups (8oz)

12.1

1

Step 1 — Baseline intake

baseline_oz = weight_lbs × 0.5

= 170 lbs × 0.5

= 85 oz

General hydration rule: half your body weight in ounces

Institute of Medicine hydration guidelines

2

Step 2 — Exercise adjustment

exercise_oz = (exercise_min / 30) × 12

= (30 / 30) × 12 = 1.00 × 12

= 12 oz

Add 12 oz per 30 minutes of physical activity

3

Step 3 — Climate adjustment

climate_oz = 0 (temperate climate)

= 0 oz

No climate adjustment needed for temperate conditions

4

Step 4 — Total in all units

total_oz = baseline + exercise + climate | liters = oz / 33.814 | cups = oz / 8

= 85 + 12 + 0 = 97 oz → 97 / 33.814 → 97 / 8

= 97 oz · 2.87 L · 12.1 cups

Key insight

At 170 lbs with 30 minutes of exercise, you need 97 oz (2.87L) of water daily. That's roughly 12.1 standard 8oz glasses — spread throughout the day, not all at once.

#ShowYourWork

Hydration Tips

  • Drink 16oz first thing in the morning before coffee
  • Carry a 32oz bottle — refill it 4× per day
  • Pale yellow urine = good hydration; dark = drink more
  • Coffee and tea count — they are not dehydrating at normal intake
  • Increase by 8oz for every hour of heat exposure beyond baseline

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