PETPALM.COMTerraGlass

Terrarium Tools & Calculators

Free, practical calculators for building and maintaining a glass garden — layer ratios, vessel volume, plant count, humidity, moss coverage, and drainage.

Substrate Layer Ratio Calculator

Enter your container's height and whether it's open or closed to get the drainage, charcoal, substrate, and top-dressing depths for a healthy stack

Jar & Vessel Volume Calculator

Pick the shape closest to your container — cylinder, sphere, bell jar, or rectangular tank — and get its total and usable substrate volume

Plant Count Calculator

Give the floor area and a plant's mature spread, choose a density, and see how many plants will comfortably fit

Terrarium Humidity Guide

Choose your vessel type and plant category and get a target humidity range plus a suggested misting cadence for your room

Moss Coverage Calculator

Enter the floor area, pad size, and coverage now to see how many pads you need and how long a sparser planting takes to fill in

Drainage Layer Calculator

Work out the drainage material height and volume needed from floor area, substrate depth, and whether the pot has a drainage hole