Terrarium Size Calculator
Plan the perfect home for your plants and small animals.
How to Use This Tool
Select the type of terrarium you plan to build (open or closed), the primary plant type, the number of plants, whether you'll include animals, and the expected maintenance level. Click Calculate to see the recommended minimum volume in gallons and liters, along with a breakdown of the calculation.
Formula and Logic
The calculator uses base space requirements per plant type: succulents (1 gallon/plant), tropical (2 gallons/plant), moss (0.5 gallon/plant), carnivorous (1.5 gallons/plant), and mixed (1.5 gallons/plant). If animals are included, additional space is added: small insects (+0.5 gallons), small reptiles (+5 gallons), amphibians (+10 gallons). A maintenance buffer is applied based on the selected level: low (0%), medium (10%), high (20%) of the subtotal (plant space + animal adjustment). The total is rounded up to the nearest whole gallon and converted to liters (1 gallon = 3.78541 L).
Practical Notes
- Terrarium type: Open terrariums are best for dry-loving plants like succulents and cacti, while closed terrariums retain humidity for tropical plants. The type you choose should match your plant selection.
- Plant spacing: These are minimum recommendations. Overcrowding can lead to poor air circulation and disease. Consider the mature size of plants, not just their current size.
- Animal considerations: If including animals, research their specific needs for space, temperature, and humidity. The animal adjustments in this calculator are general guidelines only.
- Maintenance level: Higher maintenance often means more frequent watering, pruning, and cleaning. A larger terrarium can be more stable and require less frequent attention, but the buffer is a general guideline.
- Unit conversions: 1 gallon = 3.78541 liters. Common terrarium sizes: 1 gallon ≈ 3.8 L, 5 gallons ≈ 19 L, 10 gallons ≈ 38 L.
Why This Tool Is Useful
Creating a terrarium that is too small can lead to overcrowded plants, poor air circulation, and stress for any animals. This calculator helps you start with the right size container, increasing the chances of a thriving mini-ecosystem. It also provides a breakdown so you can adjust the inputs to see how each factor affects the required size.
Frequently Asked Questions
Can I use a larger terrarium than recommended?
Yes, a larger terrarium is generally better as it provides more stable conditions and room for growth. However, very large terrariums may require more advanced climate control.
What if I have a mix of plant types?
Select "Mixed" for the plant type. This uses an average base of 1.5 gallons per plant. For a more accurate calculation, you might want to calculate each plant type separately and sum the requirements.
Do I need to adjust for the shape of the terrarium?
This calculator gives volume. The shape (tall vs. wide) can affect the suitability for certain plants and animals. For example, climbing plants and arboreal animals need height, while ground-dwelling plants and animals need floor space. Use the volume as a starting point and consider the specific needs of your chosen species.
Additional Guidance
When selecting a terrarium, look for one with a secure lid if keeping closed terrarium plants or animals that require high humidity. Ensure there is adequate ventilation, either through openings or by using a mesh lid. For open terrariums, consider a shallow, wide container to allow for good air flow. Always research the specific requirements of each plant and animal species you plan to keep, as this calculator provides only general guidelines.