Buying the wrong size tent is the most common mistake we see at the counter. Too small and you are fighting heat and cramming plants in. Too big and you have paid for a light and a fan you did not need. This guide walks you through how to pick the right tent for your room, your plant count and your budget, using the sizes you will actually find on sale in the UK.
Start with the room, not the tent
Before you look at tents, measure three things in the space where it will live:
- Floor footprint. Length and width, in metres. Remember you need about 30cm clearance on at least one side to open the door, run ducting and get at the back of the tent.
- Ceiling height. Most standard tents are 2m tall. A loft or cupboard with a 1.8m ceiling needs a short tent (1.6m or 1.8m) or a propagation tent.
- Where the air goes. Your extractor fan needs to push warm, used air somewhere. A window, a loft space or a vent into another room are all fine. If there is nowhere for the air to go, pick a smaller tent so there is less heat to deal with.
Write those numbers down. They rule out half the options straight away.
UK grow tent sizes at a glance
Tent sizes are quoted width x depth x height in centimetres or metres. These are the sizes you will see from brands like BAY6, BudBox and Gorilla.
| Tent size | Footprint | Typical use | Plants (soil/coco pots) | Light | Extractor |
|---|---|---|---|---|---|
| 60 x 60 x 140/160cm | 0.36m² | Propagation, herbs, chillies, one or two small plants | 1-2 | 100-150W LED | 4" (100mm) fan |
| 80 x 80 x 180cm | 0.64m² | Compact first grow, leafy greens, a couple of tomato plants | 2-3 | 200-300W LED | 4" or 5" fan |
| 100 x 100 x 200cm | 1m² | The most popular beginner size | 3-4 | 400-480W LED or 600W HPS | 5" (125mm) fan |
| 120 x 120 x 200cm | 1.44m² | The UK's best-selling size for a reason | 4-6 | 600-720W LED or 600W HPS | 6" (150mm) fan |
| 150 x 150 x 200cm | 2.25m² | Serious hobby grow | 6-9 | 1000W LED or 2 x 600W HPS | 6" or 8" fan |
| 240 x 120 x 200cm | 2.88m² | Two 1.2m zones side by side | 8-12 | 2 x 720W LED | 8" (200mm) fan |
| 240 x 240 x 200cm | 5.76m² | Room-sized, usually needs a dedicated circuit | 16+ | 4 x 720W LED | 10" or 2 x 8" fans |
Plant counts assume 11-20 litre pots and plants trained to fill the space. Grow bigger plants in bigger pots and you will fit fewer. Grow smaller plants in 5-7 litre pots and you can fit more.
How to pick between two sizes
If you are torn between two sizes, ask these four questions.
How many plants do you honestly want to look after? Four well-cared-for plants in a 1.2m tent will out-yield eight neglected ones in a 1.5m. Watering, feeding and checking leaves takes time, and that time scales with plant count.
What light can you afford? The tent is the cheap part. A 1.2m tent costs around £100-£160, but the 720W LED to fill it properly costs £400-£700. If your budget only stretches to a 300W light, a 1m tent will give you better results than an under-lit 1.2m one.
How much heat can the room take? Every watt of light ends up as heat in the tent. A 600W HPS in a 1.2m tent in a south-facing bedroom in July will struggle without a big fan. The same tent with a 720W LED runs cooler. If your room gets warm, either go LED or go one size down.
Will you want to grow more later? Most growers upgrade within a year. If you can afford the 1.2m tent now and fill it with a smaller light to start, you can upgrade the light later without buying a second tent.
Height matters more than people think
A standard 2m tent sounds tall until you add it all up. A light hung with its hangers takes 20-30cm. The light needs to sit 30-60cm above the canopy depending on the fixture. Pots are 25-30cm tall. That leaves roughly 1m of actual growing height for the plant itself.
If you are growing tall crops like indeterminate tomatoes, or you want to let plants stretch, look for a 2.2m or 2.4m tent. If your ceiling is low, a 1.6m or 1.8m tent works well for compact crops, chillies, herbs and leafy greens, or for anything you will train flat.
The extraction that goes with each size
A tent is only as good as the air moving through it. As a rough rule, you want to replace the air in the tent every one to three minutes. The fan sizes in the table above are a starting point. We have a full guide on choosing an extractor fan and carbon filter if you want to work it out precisely.
Two things to remember:
- Match the ducting ports. A 1.2m tent usually has 6" (150mm) ports. Buying a 4" fan means you will need reducers and you will lose airflow.
- Leave room for the filter. A carbon filter for a 6" fan is around 50cm long and 25cm wide. It hangs inside the tent and eats into your height. Factor it in.
Tent quality: what you are paying for
A £70 tent and a £160 tent of the same size do the same job on paper. The differences are:
- Pole strength. Cheap tents use thin poles that bow under a heavy LED and filter. A 720W bar light plus a filter and fan can weigh 20kg or more.
- Fabric and zips. Thicker canvas (600D or more) blocks light leaks. Zips are the first thing to fail on a budget tent.
- Ports and viewing windows. More ports means more flexibility for ducting, cables and passive intakes.
- Floor tray. A removable, waterproof tray saves your carpet when a pot overflows.
For a first grow, a mid-range tent from BAY6 or similar is the sweet spot. Spend the money you save on a better light.
Our recommendations by budget
Under £400 all-in: 80 x 80cm tent, 200-300W LED, 4" fan and filter kit. Good for herbs, salad crops, chillies or two or three compact plants.
£600-£900 all-in: 1.2 x 1.2m tent, 600-720W LED, 6" fan and filter, pots and media. This is the setup most of our customers end up with, and our complete grow tent kits are built around it.
£1,200 plus: 1.5 x 1.5m tent, 1000W LED, 6" or 8" EC fan with a controller. Room to grow and headroom to upgrade.
Still not sure?
Bring your room measurements into the shop at Unit 2 Black Lake, West Bromwich, or send them to us on WhatsApp and we will tell you which tent and light fits. We have been fitting tents to rooms for over ten years, and we would rather sell you the right 1m tent than the wrong 1.5m one.
Browse our grow tents and complete grow tent kits, or read our guide on what size LED grow light you need for your tent.