Yield formulas, g/watt benchmarks, g/m² by grow method, training multipliers, DLI targets, and realistic expectations for every skill level.
Yield prediction in cannabis cultivation is a combination of science and cultivation skill. Understanding the key variables — light power, grow space, substrate, genetics, and technique — allows growers to set realistic expectations and identify which areas of their grow to optimize for maximum output. This guide provides evidence-based yield benchmarks across every major growing method.
No single variable determines yield in isolation. The following factors interact with each other, and weakness in any one area creates a ceiling that limits overall output regardless of other inputs.
| Variable | Yield Impact | Grower Control |
|---|---|---|
| Light power (watts/PPFD) | Very high | Full control |
| Grow space (m²/ft²) | High (limits plant count/canopy) | Full control |
| Strain genetics | High (genetic ceiling) | Seed selection |
| Growing medium | Medium-High | Full control |
| Grower skill level | High (multiplier effect) | Develops with experience |
| Training techniques | 20–100% improvement | Full control |
| Temperature / VPD | Medium (stress reduces yield) | Climate control required |
| Feeding / nutrient program | Medium (errors reduce yield) | Full control |
The g/watt metric expresses yield efficiency relative to light energy consumed. It is the most commonly used benchmark for comparing grow setups and tracking personal improvement across harvests.
| Light Type | Beginner | Intermediate | Expert | Notes |
|---|---|---|---|---|
| HPS 600W | 0.25–0.4 g/W | 0.5–0.75 g/W | 0.8–1.0 g/W | Proven technology, cheap bulbs |
| HPS 1000W | 0.25–0.5 g/W | 0.6–0.85 g/W | 0.9–1.1 g/W | Higher heat management needed |
| Quality LED (Quantum Board) | 0.4–0.6 g/W | 0.75–1.0 g/W | 1.2–1.8 g/W | Best efficiency; higher upfront cost |
| Budget LED (blurple) | 0.15–0.3 g/W | 0.3–0.5 g/W | 0.4–0.6 g/W | Overstated wattage is common |
| CMH/LEC 315W | 0.4–0.6 g/W | 0.7–0.9 g/W | 0.9–1.1 g/W | Excellent terpene spectrum |
| Grow Method | Beginner g/m² | Intermediate g/m² | Expert g/m² | Cycle Speed |
|---|---|---|---|---|
| Soil (photoperiod) | 150–250g | 300–450g | 450–600g | 14–20 weeks |
| Coco coir | 200–350g | 400–600g | 600–800g | 12–18 weeks |
| DWC / Deep Water Culture | 200–350g | 450–650g | 700–1000g+ | 12–16 weeks |
| Sea of Green (SOG) | 200–350g | 350–500g | 450–700g | 8–12 weeks (fast cycles) |
| SCROG (Screen of Green) | 300–450g | 500–700g | 700–1100g | 16–24 weeks (longer veg) |
| Autoflower (any medium) | 80–150g | 150–300g | 300–500g | 8–12 weeks seed-to-harvest |
Plant training techniques manipulate cannabis plant structure to maximize light interception across the canopy. Untrained cannabis grows as a Christmas tree shape — the apical (top) cola receives maximum light while lower sites are shaded. Training flattens the canopy so all bud sites receive equal intensity.
| Technique | Stress Level | Yield Increase | Recovery Time | Best Used With |
|---|---|---|---|---|
| LST (Low Stress) | Low | 20–40% | None | Autoflowers, beginners |
| Topping | Medium | 30–60% | 5–10 days | Photoperiod, medium experience |
| FIMing | Medium | 40–70% | 5–10 days | More cola sites than topping |
| SCROG | Low-Medium | 50–100% | Ongoing management | Indoor photoperiod, high yield goals |
| Supercropping | High | 30–50% | 7–14 days | Experienced growers, veg phase only |
| Lollipopping | Medium | Top-cola weight +20–40% | 3–7 days | Quality over quantity, SOG |
DLI (Daily Light Integral) measures the total amount of photosynthetically active radiation (PAR) a plant receives over a full day. It is expressed in moles of light per square meter per day (mol/m²/day) and is considered the most accurate predictor of photosynthetic potential and yield capacity for a given grow setup.
| Growth Stage | Minimum DLI | Optimal DLI | Maximum Useful DLI |
|---|---|---|---|
| Seedling | 6 | 10–20 | 25 |
| Vegetative | 20 | 35–45 | 50 |
| Flowering | 30 | 45–60 | 65–70 |
New growers should not measure their first harvest against expert benchmarks. Skill development is the most significant yield multiplier in cannabis cultivation, and the gap between first-grow results and optimized results is typically 2–4x across equivalent setups.
Outdoor cannabis plants have access to free sunlight and unlimited vertical and horizontal growth space, making per-plant yields dramatically higher than indoor plants. However, outdoor yields are harder to predict due to weather variability.
Every strain has a genetic ceiling for yield. Breeder-stated yield figures are typically obtained under optimal commercial conditions and represent maximum potential, not average results. Strains marketed as "500g/m²" in real home grow conditions might yield 300–350g/m² for an intermediate grower.
Use the following parameters to estimate your expected yield before planting:
The benchmark for HPS lighting is 0.5 to 1 gram per watt. Modern LED grow lights perform better, with experienced growers achieving 1 to 1.5 grams per watt. Beginners should expect 0.25 to 0.5 grams per watt as a realistic first-run benchmark.
Indoor yields vary by method: soil grows average 300 to 500g per m², coco coir achieves 500 to 700g per m², and DWC hydro pushes 600 to 900g per m² in expert hands. SCROG with quality LED lighting can reach 700–1100g per m².
Training methods can increase yields by 20 to 100% by maximizing light distribution. LST increases yield 20–40%, SCROG can double yield, and topping/FIMing increase cola count significantly. All training works by flattening the canopy so every bud site receives maximum light intensity.
Cannabis in veg performs optimally at a DLI of 35 to 45 mol/m²/day. Flowering cannabis benefits from 45 to 60 DLI. Exceeding 65 DLI during flowering offers diminishing returns for most strains and significantly increases heat management requirements.