🚰 Sink Capacity Calculator
Enter your bowl's inside length, width, and depth to find how much water it holds — in gallons and liters — for a square-cornered or a rounded basin.
🚰 Bowl Dimensions
What is a Sink Capacity Calculator?
It turns your bowl measurements into the volume of water the sink can hold. From the inside length, width, and depth it computes the volume in cubic inches, applies a shape factor for a rounded basin, and converts the result to US gallons and liters — the brim-full capacity with the drain plugged.
Use it to compare sinks when you're shopping, to size a basin for soaking pots or filling buckets, or to understand how much water a full sink represents. The figures are estimates for planning — real bowls taper and have drain wells, so expect a little less in practice.
❓ Frequently Asked Questions
How does the calculator work out a sink's capacity?
It multiplies the bowl's inside length, width, and depth to get its volume in cubic inches, then converts that to US gallons (231 cubic inches per gallon) and liters (3.78541 liters per gallon). For a rounded or curved basin it keeps about 85% of the box volume, since curved corners and a sloped bottom remove space a plain box calculation would count.
Should I measure the inside or the outside of the bowl?
Measure the inside of the bowl — the wetted length, width, and depth you actually fill. The outside dimensions include the rim and walls and would overstate how much water the sink holds. Depth is the distance from the bottom of the bowl up to the point where it would overflow.
Why is my sink's real capacity less than the figure shown?
The result is the brim-full volume with the drain plugged. In everyday use you rarely fill to the very top, the drain opening and any overflow sit below the rim, and a strainer basket displaces a little water. Treat the number as the maximum and expect real fills to be somewhat lower.
How many gallons does a typical kitchen sink hold?
A standard single-bowl kitchen sink around 30 by 18 by 9 inches holds roughly 20 gallons brim-full; a deep farmhouse sink can hold more, and a shallow bar or prep sink far less. Enter your own bowl's measurements for a figure that matches your sink rather than an average.