Turtle Tank Size Calculator
Calculate the minimum tank size for your turtle based on species, size, and number of turtles.
Recommended Tank Size
Turtle tank sizing follows a general rule: 10 gallons of water per inch of shell length.
Formula:
Minimum gallons = Shell length (inches) × 10
For multiple turtles, add 50% more space per additional turtle.
Recommended minimums by species:
| Species | Adult Size | Min Tank (gal) | Min Tank (L) |
|---|---|---|---|
| Red-eared slider | 10–12" | 100–120 | 380–455 |
| Painted turtle | 8–10" | 80–100 | 300–380 |
| Musk turtle | 4–5" | 40–50 | 150–190 |
| Map turtle | 7–10" | 70–100 | 265–380 |
| Box turtle (land) | 5–7" | 40 gal enclosure | N/A |
| Mud turtle | 4–5" | 40–50 | 150–190 |
Tank setup requirements:
- Water depth: At least 1.5–2× shell length
- Basking area: Dry platform with heat lamp (85–95°F / 29–35°C)
- Water temperature: 75–80°F (24–27°C)
- Filtration: Rated for 2–3× the tank volume
- UVB lighting: Essential for shell health
Common mistake: Starting with a small tank and “upgrading later.” Buy the adult-size tank from the start — turtles grow quickly.