About AquariumVolume.com

AquariumVolume.com is a focused calculator resource dedicated entirely to aquarium volume. We are not a general aquarium hobbyist site, a product retailer, or a fish care guide. Our single purpose is to provide free, accurate volume calculators for every aquarium tank shape in common use — from the standard rectangular glass box to curved, corner, polygon, and custom designs. Every page on this site exists to help you determine exactly how many gallons or litres your tank holds.

Who Built This Site

Created and maintained by Sheikh Abdullah Bin Islam, the site owner and developer. AquariumVolume.com was built to solve a specific problem: general aquarium sites treat volume as an afterthought, and calculators for non-rectangular shapes like bow fronts, hexagons, and corner cylinders are often missing or unreliable. This site focuses entirely on getting that one calculation right, for all 20 common tank shapes.

The goal is a calculator resource accurate enough to be useful for medication dosing decisions, not just curiosity — built on standard geometry formulas and unit conversions rather than aquarium-specific expertise.

Why Accurate Aquarium Volume Matters

Knowing your tank’s precise water volume matters more than many fishkeepers realise. Medication and water treatment dosing is calculated per gallon or litre — an error of even 20% can mean underdosing a parasite treatment or dangerously overdosing a supplement. Stocking density recommendations depend entirely on accurate volume. Equipment sizing — heater wattage, filter flow rate, protein skimmer capacity for reef tanks — is also specified by volume. A calculator that returns the wrong figure sets off a chain of incorrect decisions throughout the life of your aquarium.

Our Methodology

Every calculator on this site applies the correct geometric formula for that specific tank shape. A rectangular tank uses length × width × height divided by 231 to convert cubic inches to US gallons. A bow front tank requires an additional half-ellipse calculation for the curved section. A hexagonal tank uses the regular hexagon area formula. A corner cylinder is exactly one quarter of a full cylinder’s volume. The formula is displayed on every calculator page so you can verify the math yourself. Results are shown in both US gallons and litres simultaneously.

All calculators ask for inside dimensions, not outside measurements. The glass or acrylic walls of an aquarium have meaningful thickness — typically ¼ inch on small tanks and up to ¾ inch on large display setups. Measuring the exterior and treating it as the interior will overstate your volume by 5–8% on large tanks. Our measurement guide on each calculator page explains exactly where to place your tape measure to get the correct inside dimension.

AquariumVolume.com uses standard geometry formulas, unit conversions, and common aquarium size conventions as a reasonableness check. Where published tank dimensions are available, calculator outputs are compared against common nominal aquarium sizes as a sanity check. For the most accurate result, always measure the inside dimensions of your own tank rather than relying on a nominal label size. Where nominal label volumes differ from calculated volumes, we explain why on the dedicated aquarium volume by brand reference page.

What This Site Covers

AquariumVolume.com launched in 2026 and covers 20 individual tank shape calculators, 5 calculator category hubs, 5 side-by-side shape comparison guides, reference pages and measurement guides, and specialist tools, with localized versions of core calculators and guides available across 11 languages. All content is focused exclusively on aquarium volume — we do not cover fish care, species guides, product reviews, or any topic outside of volume calculation and measurement.

Start with the aquarium volume calculator hub to browse all 20 shapes, or use the aquarium shapes guide to identify your tank type. For reference data, the volume by size table and volume by brand table cover standard and manufacturer-specific sizes.

Last updated: August 2026. For questions or corrections, use the contact page. See our privacy policy and terms of use.