Every grower wants bigger yields. The problem is that "yield" is poorly defined in most growing communities — "I got 500 grams!" means nothing without knowing how much light, space, and time produced it. A grower running a 600W light for 16 weeks who harvests 500 grams is doing worse than a grower with a 300W light for 12 weeks who harvests 300 grams.
The only meaningful yield metric is grams per watt (g/W) — how much dried flower you produced per watt of light input. This normalizes for equipment differences and lets you compare grows objectively.
How to measure yield
Grams per watt (g/W)
Formula: total dried weight (grams) ÷ light wattage (actual wall draw)
| g/W | Rating | What it means |
|---|---|---|
| Below 0.5 | Below average | Significant room for improvement |
| 0.5–0.75 | Average | Typical for beginners and intermediate growers |
| 0.75–1.0 | Good | Competent grower, optimized environment |
| 1.0–1.5 | Excellent | Well-tuned system, experienced grower |
| 1.5+ | Elite | Commercial-level optimization, everything dialed |
Example: 300g from a 300W LED = 1.0 g/W (good). 300g from a 480W LED = 0.63 g/W (average — room for improvement despite the absolute yield being the same).
Other useful metrics
- Grams per square foot: total dried weight ÷ canopy area. Typical: 1–2 oz/sq ft
- Grams per day of flower: total dried weight ÷ days in flower. Normalizes for strain differences in flower time
- Yield per plant is the least useful metric — a single plant can yield 1 oz or 12 oz depending on training, veg time, and container size
The yield hierarchy
The factors that affect yield, ranked by impact: