Cannabis Yield Calculator
Estimate how much cannabis you can grow — and discover the best high-yield strains for your setup. Works for indoor tents, outdoor gardens, and everything in between.
Calculate Your Yield
Quick Yield Answers
120×120cm tent yield?
225–450g
per harvest, LED lighting
Plants per m²?
1–2
depending on training
Yield per plant?
30–140g
indoor, genetics dependent
60×60cm tent yield?
55–115g
per harvest, LED lighting
Autoflower yield?
30–115g
per plant, 8–10 weeks
How Much Cannabis Can You Yield?
Cannabis yield depends on four main factors: grow space size, lighting, genetics, and grower experience. Indoor growers using LED lights typically harvest 155 to 305 grams per square metre, while HPS setups can push 230 to 380 g/m². Outdoor plants have the highest potential — a single plant in open ground can produce 30 to 140+ grams depending on climate and strain.
Our yield calculator uses these baseline ranges and adjusts for your experience level and seed type. Autoflowering cannabis seeds allow more harvest cycles per year (up to 4 indoors), while feminized photoperiod strains typically produce larger individual harvests.
Cannabis Yield Per Square Foot — What to Expect
| Light Type | Yield / m² | Best For |
|---|---|---|
| LED | 155–305 g/m² | Energy efficiency, full spectrum |
| HPS | 230–380 g/m² | Maximum intensity, proven results |
| CFL | 75–155 g/m² | Small spaces, supplemental |
| Sunlight (Outdoor) | 230–610 g/m² | Highest potential per plant |
These ranges represent realistic expectations for properly maintained grows. Factors like nutrient management, VPD control, and plant training can push you toward the higher end.
How to Increase Cannabis Yields
Choose High-Yield Genetics
Strain selection is the #1 factor. Some strains are bred specifically for heavy harvests.
Shop High Yield Seeds →Use Training Techniques
LST, topping, and ScrOG can increase yields 20-40% by maximizing light exposure.
Read Training Guide →Optimize Your Lighting
More light = more yield (to a point). LED and HPS both deliver strong results.
Read Light Guide →Dial In Nutrients
Proper feeding through each stage prevents deficiencies and maximizes bud development.
Read Nutrient Guide →Best High-Yield Cannabis Strains
The right genetics make the biggest difference. These strains consistently produce above-average harvests when given proper care. Whether you grow autoflowering seeds for faster cycles or feminized photoperiod seeds for maximum single-harvest weight, choosing yield-oriented genetics is your foundation.
Indoor vs Outdoor Yield Comparison
💡 Indoor Growing
- • Typical: 155–380 g per m²
- • 2–4 harvests per year
- • Full control over environment
- • Year-round growing
- • Higher startup cost, lower risk
☀️ Outdoor Growing
- • Typical: 30–140+ g per plant
- • 1 harvest per year (fall)
- • Free sunlight, lower costs
- • Larger plants possible
- • Weather and pest risks
How Accurate Is This Cannabis Yield Calculator?
Our calculator provides realistic yield ranges based on established growing data — not inflated marketing numbers. The estimates account for grow space, lighting efficiency, seed genetics, and grower experience. However, actual harvests depend on many variables including nutrient management, environmental control, training techniques, and strain-specific characteristics.
We deliberately show conservative ranges. Beginners should expect results closer to the lower end, while experienced growers using high-yield cannabis seeds with proper training can consistently hit or exceed the upper range. The “optimized” number represents what skilled growers achieve with premium genetics, optimized lighting, and dialed-in environments.
This calculator is based on real grow data and industry-standard yield ranges used by indoor and outdoor cultivators across Australia. The logic reflects what 200,000+ Australian growers have reported when using seeds from Royal King Seeds.
Use these estimates as a planning starting point. Your actual results will improve with each grow cycle as you learn your specific environment. For the most accurate projections, factor in your strain's genetic potential, your lighting setup, and whether you use plant training techniques.
Frequently Asked Questions
How much weed can I grow in a 120×120cm tent?
A 120×120cm tent (1.44 m²) with LED lighting typically yields 225–450g per harvest for an intermediate grower. Beginners can expect 170–340g. Using high-yield genetics and training techniques can push you toward the upper range.
How many plants per square metre for cannabis?
For autoflowers, plan 11–16 plants per square metre. For feminised photoperiod plants with training, around 11 per square metre is standard. In a 120×120cm tent, most growers run 4–9 plants depending on pot size and training method.
Cannabis yield LED vs HPS — which is better?
Modern LEDs match or exceed HPS yields while using 30–40% less electricity. HPS delivers 230–380 g/m² while quality LEDs deliver 155–305 g/m². The gap has closed significantly, and LED advantages in heat management and spectrum control make them the preferred choice for most growers.
How much does an outdoor cannabis plant yield?
A single outdoor cannabis plant can yield 30–140+ grams depending on strain, climate, and growing season length. In warm climates with long seasons (Queensland, Northern Territory), plants can reach massive sizes. High-yield outdoor strains like Big Bud and Critical Mass are bred for heavy harvests.
How do autoflower yields compare to feminized?
Individual autoflower plants yield less than feminized photoperiod plants (typically 30–115g vs 55–225g per plant). However, autoflowers complete in 8–10 weeks and allow 3–4 harvests per year indoors, often matching or exceeding annual yields from photoperiod plants.