Cat Water Intake Calculator
Estimate your cat’s daily water needs based on weight and diet (wet vs dry). Get a simple range plus a food-adjusted “water to drink” target.
Quick answer
Typical daily water range
Many estimates fall around 40–60 mL per kg of body weight per day (from all sources: drinking water + moisture in food). Wet food can cover a big part of this.
If your cat suddenly drinks much more or much less than usual, or shows signs of illness, contact a vet.
Inputs
Used to estimate daily needs.
mL per kg per day (typical range: 40–60).
Diet adjustment (moisture from food)
We estimate how much water comes from food.
If you know your cat’s food moisture intake.
Small adjustment to the target range.
If you track how much your cat drinks daily.
When to contact a vet
Sudden changes in drinking can be important. If your cat’s water intake noticeably increases or decreases, or if you see vomiting, lethargy, weight loss, or frequent urination, contact a veterinarian. This tool is for planning and awareness — not diagnosis.
How this calculator works (formulas)
We estimate a daily water target using a simple weight-based approach:
Step 1: Convert weight to kg
kg = lb × 0.453592 (if you entered pounds)
Step 2: Total water need (all sources)
Total (mL/day) = weight(kg) × rate(mL/kg/day) × activity factor
Typical rate is often estimated around 40–60 mL/kg/day (all sources).
Step 3: Water to drink (diet adjusted)
Drink target = max(0, total need − water from food)
Wet food contributes more water than dry food. If you select “custom,” you can enter your own estimate.
FAQ
Do cats on wet food need to drink water?
Many still drink some water, but wet food can provide a large share of daily water intake. That’s why this calculator subtracts an estimated “water from food” amount.
Why might a cat drink much more than usual?
Increased drinking can be linked to multiple conditions. If intake changes noticeably or comes with other symptoms, contact a veterinarian.
Is the “mL/kg” rate exact?
It’s an estimate used for general planning. Real needs vary with diet, temperature, activity, and health. Use your cat’s normal baseline and vet guidance for medical concerns.