How do I calculate cannabis yield?

To calculate cannabis yield, you need: total wattage of your lights, grow area in square meters, efficiency (grams per watt), grower experience level, and growing method. Our calculator uses these factors to estimate a yield range (minimum, maximum, and average).

What is the difference between LED, HPS, and CMH lights?

LED lights are more energy-efficient and produce less heat, typically requiring 15% less wattage for the same PPFD. HPS (High Pressure Sodium) lights are traditional and powerful but generate more heat. CMH (Ceramic Metal Halide) lights offer a full spectrum similar to natural sunlight.

What is yield efficiency (g/W)?

Yield efficiency (grams per watt) measures how many grams of dried flower you can produce per watt of light. Beginners typically achieve 0.5 g/W, intermediate growers 0.75 g/W, advanced growers 1.0 g/W, and professional growers can reach 1.25-1.5 g/W.

What is the best growing method for maximum yield?

SCROG (Screen of Green) typically produces the highest yields (up to 20% more than normal), followed by SOG (Sea of Green) at 10% more. Normal growing methods are simpler but produce lower yields. The method choice depends on your experience and space constraints.

How accurate is the yield calculator?

Our calculator provides theoretical estimates based on industry-standard formulas. Actual yields vary significantly based on genetics, environment, nutrients, temperature, humidity, CO2 levels, and grower skill. Use the calculator as a planning tool, not a guarantee.

Yield & Grow Light Calculator

Estimate your cannabis yield based on lighting setup, grow area, and experience level. Calculate required watts for optimal growth.

Yield Calculator

Your Setup

Light Type LED is most efficient (15% less watts needed). HPS is traditional and powerful. CMH offers full spectrum light.

LED HPS CMH

Total Watts Total wattage of your lighting setup.

Grow Area (m²) Enter the total growing area in square meters. This is the floor space where your plants will be placed. For example: a 1.2m x 1.2m tent = 1.44 m². A 4ft x 4ft tent ≈ 1.48 m².

Floor area where plants grow. Example: 1.2m × 1.2m = 1.44 m²

Efficiency & Method

Your Efficiency Level (g/W) Efficiency (g/W) = grams per watt. This measures how well you convert light into yield. It depends on your experience, setup quality, and growing conditions.

Beginner: 0.5 g/W (first grows, basic setup)
Intermediate: 0.75 g/W (good environmental control)
Advanced: 1.0 g/W (optimized conditions)
Expert: 1.25 g/W (professional techniques)
Professional: 1.5 g/W (commercial level with CO2)

What is g/W? Grams per watt measures how many grams of dried flower you produce per watt of light. This combines your experience, setup quality, and growing skills into one metric.

Growing Method SCROG can increase yield by 20%, SOG by 10%. Normal method is simpler but produces lower yields.

Normal SOG SCROG

Estimated Yield Range

Minimum

grams

Average

grams

Maximum

grams

Yield per m²

g/m²

Yield per Watt

g/W

Yield Range

0 - 0 g

Watt Calculator

Your Grow Space

Grow Area (m²) Enter the total growing area in square meters. This is the floor space where your plants will be placed. For example: a 1.2m x 1.2m tent = 1.44 m². A 4ft x 4ft tent ≈ 1.48 m².

Floor area where plants grow. Example: 1.2m × 1.2m = 1.44 m²

Light Configuration

Light Type LED is most efficient (15% less watts needed). HPS is traditional and powerful. CMH offers full spectrum light.

LED HPS CMH

Desired Intensity Light intensity affects yield. Low is for seedlings/early veg. Medium is optimal for most grows. High requires excellent environment control.

Low (300-400 W/m²) Medium (400-600 W/m²) High (600-800 W/m²)

Disclaimer: All calculations are theoretical estimates for legal cultivation purposes only. Actual yields vary based on genetics, environment, nutrients, and grower skill. This tool is for planning and educational purposes. Valid for legal cultivation and permitted plant use only.

What is a Yield Calculator?

A yield calculator is a tool that helps you estimate the potential harvest from your cannabis cultivation setup. By inputting key variables like lighting wattage, grow area, efficiency, and experience level, you can get realistic yield projections to help plan your grow operation.

How to Calculate Cannabis Yield

Calculating cannabis yield involves several factors:

Total wattage of your lighting setup (LED, HPS, or CMH)
Grow area in square meters (the floor space where plants are placed)
Efficiency (g/W) - grams per watt, which varies by grower experience (0.5-1.5 g/W typical range)
Grower level - experience affects actual yield (beginners achieve ~70% of potential, professionals ~115%)
Growing method - SCROG can increase yield by 20%, SOG by 10% compared to normal methods
Light type - LED is most efficient, requiring ~15% less wattage for the same PPFD output

Understanding Yield Efficiency (g/W)

Yield efficiency, measured in grams per watt (g/W), indicates how effectively you convert light energy into harvest weight. This metric varies significantly based on:

Beginner (0.5 g/W): First-time growers or those with basic setups
Intermediate (0.75 g/W): Experienced growers with good environmental control
Advanced (1.0 g/W): Skilled growers with optimized conditions
Expert (1.25 g/W): Professional-level cultivation with perfect conditions
Professional (1.5 g/W): Commercial operations with CO2 supplementation and ideal genetics

How Many Watts Do I Need for My Grow Space?

The required wattage depends on your grow area and desired light intensity:

Low intensity (300-400 W/m²): Suitable for seedlings, early vegetative growth, or low-light plants
Medium intensity (400-600 W/m²): Optimal for most cannabis grows, providing excellent yields without excessive heat
High intensity (600-800 W/m²): Maximum yield potential, requires excellent ventilation, CO2 supplementation, and environmental control

Note: LED lights are approximately 15% more efficient than HPS or CMH, meaning you need fewer watts to achieve the same PPFD (Photosynthetic Photon Flux Density).

LED vs HPS vs CMH: Which is Best for Yield?

Each light type has advantages:

LED: Most energy-efficient, produces less heat, longer lifespan, requires ~15% less wattage for same output. Best for most home growers.
HPS (High Pressure Sodium): Traditional, powerful, proven track record. Generates more heat, higher energy consumption. Still popular for large operations.
CMH (Ceramic Metal Halide): Full-spectrum light similar to natural sunlight, good color rendering. Moderate efficiency between LED and HPS.

Growing Methods: Normal, SOG, and SCROG

Your growing method significantly impacts yield:

Normal: Standard growing without special training. Simplest method, baseline yield.
SOG (Sea of Green): Many small plants with minimal veg time. Can increase yield by ~10% through better light distribution and faster turnaround.
SCROG (Screen of Green): Training plants under a screen to create an even canopy. Can increase yield by ~20% by maximizing light penetration and bud development.

Important Notes About Yield Estimates

All yield calculations are theoretical estimates. Actual yields vary significantly based on:

Genetics and strain characteristics
Environmental conditions (temperature, humidity, CO2 levels)
Nutrient quality and feeding schedule
Pest and disease management
Harvest timing and curing process
Grower skill and attention to detail

Use this calculator as a planning and educational tool to understand potential yields and optimize your setup. Always aim for legal cultivation practices and permitted plant use only.