🐢 Turtle Tank Size Calculator
Determine how much water and basking area your aquatic turtle needs to stay healthy and active.
Habitat tip
Measure shell length straight across the carapace. Provide basking platforms, UVB lighting, and powerful filtration for clean water.
How to Use This Calculator
Measure shell length
Use calipers or a flexible tape to capture straight carapace length.
Enter the turtle count
Only house compatible turtles; increase space for territorial males.
Plan the habitat
Combine recommended volume with a basking dock, UVB bulb, and strong filter.
Formula
Gallons = max(Shell Lengthin × 10, 20) × Number of Turtles
Liters = Gallons × 3.78541
The “10 gallons per inch” rule provides a baseline. Increase volume for active species, minimal outdoor time, or future growth.
Full Description
Aquatic turtles generate significant waste. Adequate water volume dilutes toxins, while basking platforms and UVB light support shell health and metabolism.
Track growth every few months and plan upgrades before turtles outgrow their habitat. Outdoor ponds or stock tanks may suit large adults.
Frequently Asked Questions
Can multiple turtles share one tank?
Only if they are similarly sized and non-aggressive. Provide ample space and hiding areas to reduce stress.
How often should I clean the tank?
Perform 25–30% water changes weekly and deep clean monthly, depending on filtration and feeding habits.
Do I still need UVB with high water volume?
Yes. UVB lighting is essential for calcium metabolism regardless of tank size.
What if my turtle grows larger?
Recalculate shell length annually and upgrade the habitat before space becomes cramped.