Advanced Pot Size & Soil Calculator

The Science of Repotting

Most people think repotting is just giving a plant "more room". But it's actually about refreshing the nutrient supply and improving oxygen airflow to the roots.

Our advanced calculator doesn't just give you a number. It gives you a recipe for success, tailoring the soil mix and care advice to your specific plant family.

Master Soil Recipes

Plant Family	The Perfect Mix	Why it works
Aroids (Monstera, Philo)	40% Soil, 30% Bark, 20% Perlite, 10% Charcoal	Chunky bits mimic their natural epiphytic habitat (growing on trees).
Succulents / Cacti	50% Potting Soil, 50% Grit (Pumice/Perlite)	Extreme drainage ensures roots never sit in dampness.
Ferns / Calatheas	60% Soil, 20% Coco Coir, 20% Perlite	Coco coir holds moisture evenly without being soggy.
Ficus / Trees	80% Soil, 20% Sand/Perlite	Denser structure needed to support heavy top growth.

Choosing Your Armor: Pot Materials

Terra Cotta

The Classic Clay

Super Breathable: Walls wick water.
Good for: Over-waterers & Succulents.
Con: Heavy, breakable, dries fast.

Plastic / Resin

The Modern Standard

Retains Water: Good for tropicals.
Lightweight: Easy to move large plants.
Con: Can suffocate roots if overwatered.

Glazed Ceramic

For Show

Decoration: Matches decor perfectly.
Heavy: Prevents tall plants tipping.
Con: Often lacks drainage holes (Check!).

The 5-Step Repotting Ritual

Water Beforehand

Water your plant 1-2 days before repotting. This ensures the roots are hydrated and the soil holds together, reducing shock.

Tease the Roots

Gently remove the plant. If roots are circling tightly (rpot bound), gently massage and loosen them so they can grow outward into the new soil.

Set the Height

Add a base layer of soil. Place the plant so the top of the root ball is ~1 inch below the rim. Never bury the stem deep!

Fill the Sides

Fill the gaps with your fresh mix. Tap the pot gently on the table to settle the soil—don't pack it down hard with your hands (roots need air).

Water Thoroughly

Water until it runs out the bottom drainage holes. This settles the soil around roots and removes air pockets.

Frequently Asked Questions

What is the best soil mix for Monstera?

Monsteras are Aroids that love air exposure at the roots. The best mix is 40% quality potting soil, 30% orchid bark (for chunky aeration), 20% coarse perlite (drainage), and 10% horticultural charcoal (sweetens soil).

Why is 'overpotting' dangerous?

When a small plant is in a huge volume of wet soil, the roots cannot drink the water fast enough. The stagnant water depletes oxygen, leading to anaerobic bacteria growth and root rot. Always increase pot size incrementally.

Terra Cotta vs Plastic Poll - Which is better?

Terra Cotta is porous, wicking moisture away from roots—perfect for succulents or chronically over-watered plants. Plastic retains moisture longer, which moisture-loving ferns and calatheas prefer. It also doesn't dry out as fast in summer.

How deep should I plant the root ball?

The top of the root ball should be about 0.5 to 1 inch below the rim of the pot. Never bury the stem deeper than it was originally growing, as this causes stem rot. Leave space at the top for watering.

What is transplant shock?

Transplant shock is when a plant droops or drops leaves after repotting due to root damage. To minimize it: don't disturb the root ball unnecessarily, water immediately after repotting, and keep the plant out of direct sun for a week.

Do I really need drainage holes?

Yes! Without drainage, water pools at the bottom. Even if the top feels dry, the bottom roots drown. If you love a decorative pot without holes, use it as a 'cache pot'—keep the plant in a plastic nursery pot and just slip it inside.

How many liters is a standard bag of soil?

In the US, small bags are often 8 dry quarts (~8.8 Liters). Large bags are 1 or 2 cubic feet (28 or 56 Liters). Our calculator tells you exactly how much you need so you don't buy too little.

Can I put rocks at the bottom for drainage?

Myth busted! Putting gravel at the bottom actually RAISES the water table (due to capillary action physics), keeping wet soil closer to the roots. It's better to use a mesh screen over the hole and fill the entire pot with high-quality soil.