Caffeine/alcohol impact?

Increase fluids if consuming diuretics.

Yes—balance intake and listen to your body; this is not a medical prescription.

Why a simple formula?

It's a quick, non-medical guideline for everyday use.

everyday calculator

Water Intake by Weight Calculator

Estimate daily water intake based on body weight, activity minutes, and climate for a simple hydration target.

Results

Ounces per day: 125.90
Cups per day: 15.74
Liters per day: 3.72

How to use this calculator

Enter your weight and unit.
Enter daily activity minutes.
Choose climate (moderate vs hot/humid).
See ounces, cups, and liters per day.

Inputs explained

Weight: Your body weight to set baseline hydration.
Activity minutes: Daily exercise minutes to add extra water.
Climate: Hot/humid adds a 10% buffer.

How it works

Baseline = weight(lb) × 0.67 oz. Activity adds ~0.4 oz per minute. Hot climate adds 10% buffer.

Formula

Baseline oz = Weight(lb) × 0.67
Activity oz ≈ Minutes × 0.4
Total oz = (Baseline + Activity) × Climate factor
Cups = Total oz ÷ 8
Liters = Total oz × 0.02957

When to use it

Setting a daily water goal for training or general wellness.
Adjusting intake upward for hot weather or more activity.
Getting a quick, non-medical hydration target.

Tips & cautions

Spread intake through the day; adjust for high caffeine/alcohol days.
Hot climates may need more than 10%—add a buffer if you sweat heavily.
Listen to thirst cues; this is a general guideline, not medical advice.
Non-medical; does not account for medical conditions or specific hydration needs.
Activity multiplier is a simplification; heavy endurance may require more.

Worked examples

170 lb, 30 min, moderate climate

Baseline ≈ 114 oz
Activity ≈ 12 oz
Total ≈ 126 oz (~15.8 cups, 3.72 L)

70 kg, 60 min, hot climate

Weight ≈ 154 lb
Baseline ≈ 103 oz
Activity ≈ 24 oz
Hot factor 1.1 → Total ≈ 139 oz (~17.4 cups, 4.11 L)

Deep dive

This water intake by weight calculator estimates daily ounces, cups, and liters using your weight, activity, and climate.

Use it for a quick hydration goal; adjust upward for heavy sweat or endurance training.

FAQs

Medical conditions?: Consult a clinician; this is general guidance only.
Athletes/endurance?: May need more; use as a baseline and adjust with a coach or dietitian.
Caffeine/alcohol impact?: Increase fluids if consuming diuretics.
Can I overhydrate?: Yes—balance intake and listen to your body; this is not a medical prescription.
Why a simple formula?: It's a quick, non-medical guideline for everyday use.

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Non-medical estimate for general hydration guidance. Consult a healthcare professional for personalized needs or if you have medical conditions.