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Conversion Tables

Last updated: April 29, 2025 Data & Measurement Tools

Contents

Area Conversions

Common Growing Area Units

To Convert FromToMultiply ByExample
Square feet (ft²)Square meters (m²)0.0929100 ft² = 9.29 m²
Square meters (m²)Square feet (ft²)10.76410 m² = 107.64 ft²
AcresSquare feet (ft²)43,5601 acre = 43,560 ft²
AcresHectares (ha)0.40475 acres = 2.02 ha
Hectares (ha)Acres2.4711 ha = 2.47 acres
Square feet (ft²)Canopy plants (indoor)0.25-1100 ft² = 25-100 plants

Plant Spacing Quick Reference

Growing MethodPlants per Square MeterPlants per Square FootRecommended Spacing
Indoor (SOG)9-160.8-1.525-30 cm (10-12")
Indoor (Standard)4-90.4-0.830-45 cm (12-18")
Indoor (SCROG)1-40.1-0.445-90 cm (18-36")
Greenhouse2-60.2-0.640-70 cm (16-28")
Outdoor0.25-10.02-0.11-2 m (3-6')

Volume Conversions

Liquid Volume

To Convert FromToMultiply ByExample
Gallons (US)Liters (L)3.7855 gallons = 18.93 L
Liters (L)Gallons (US)0.26410 L = 2.64 gallons
Milliliters (mL)Fluid ounces (fl oz)0.03430 mL = 1.01 fl oz
Fluid ounces (fl oz)Milliliters (mL)29.5748 fl oz = 236.59 mL
Cups (US)Milliliters (mL)236.591 cup = 236.59 mL
Teaspoons (tsp)Milliliters (mL)4.9291 tsp = 4.93 mL
Tablespoons (tbsp)Milliliters (mL)14.7871 tbsp = 14.79 mL

Growing Media Volume

To Convert FromToMultiply ByExample
Cubic feet (ftÂł)Gallons (US)7.4812 ftÂł = 14.96 gallons
Cubic feet (ftÂł)Liters (L)28.3171 ftÂł = 28.32 L
Gallons (US)Cubic feet (ftÂł)0.13410 gallons = 1.34 ftÂł
Liters (L)Cubic feet (ftÂł)0.03520 L = 0.71 ftÂł

Common Container Sizes

Container SizeVolumeAppropriate for
1 gallon3.79 LYoung veg plants, 2-3 weeks
3 gallon11.4 LSmall-medium plants, 3-5 weeks
5 gallon18.9 LMedium plants, 4-8 weeks
7 gallon26.5 LMedium-large plants, 6-10 weeks
10 gallon37.9 LLarge indoor, small outdoor
15-20 gallon56.8-75.7 LLarge plants, outdoor
25+ gallon94.6+ LFull-season outdoor

Weight Conversions

Metric to Imperial

To Convert FromToMultiply ByExample
Grams (g)Ounces (oz)0.03528 g = 0.99 oz
Kilograms (kg)Pounds (lb)2.2051 kg = 2.21 lb
Milligrams (mg)Grains0.01541000 mg = 15.4 grains

Imperial to Metric

To Convert FromToMultiply ByExample
Ounces (oz)Grams (g)28.351 oz = 28.35 g
Pounds (lb)Kilograms (kg)0.4545 lb = 2.27 kg
GrainsMilligrams (mg)64.79910 grains = 648 mg

Cannabis Industry Specific

Common NameMetric EquivalentImperial Equivalent
Gram1 g0.035 oz
Eighth3.5 g1/8 oz
Quarter7 g1/4 oz
Half ounce14 g1/2 oz
Ounce28.35 g1 oz
Pound453.59 g16 oz
Kilogram1000 g35.27 oz

Concentration Conversions

PPM and EC Conversion (Approximate)

PPM (500 scale)PPM (700 scale)EC (mS/cm)CFNotes
000.00Pure water
100-250140-3500.2-0.52-5Seedlings, cuttings
300-500420-7000.6-1.06-10Young veg
500-750700-10501.0-1.510-15Established veg
750-9501050-13301.5-1.915-19Late veg/pre-flower
950-11001330-15401.9-2.219-22Early/mid flower
1100-14001540-19602.2-2.822-28Peak flower
800-10001120-14001.6-2.016-20Late flower
400-0560-00.8-0.08-0Flush

Conversion Formulas

To Convert FromToFormula
EC (mS/cm)PPM (500 scale)PPM = EC × 500
EC (mS/cm)PPM (700 scale)PPM = EC × 700
PPM (500 scale)EC (mS/cm)EC = PPM á 500
PPM (700 scale)EC (mS/cm)EC = PPM á 700
PPM (500 scale)PPM (700 scale)700 scale = 500 scale × 1.4
PPM (700 scale)PPM (500 scale)500 scale = 700 scale á 1.4

Percentage to PPM

PercentagePPM
0.01%100 ppm
0.05%500 ppm
0.1%1,000 ppm
0.5%5,000 ppm
1.0%10,000 ppm

Temperature Conversions

Conversion Formulas

To Convert FromToFormulaExample
Celsius (°C)Fahrenheit (°F)°F = (°C × 9/5) + 3220°C = 68°F
Fahrenheit (°F)Celsius (°C)°C = (°F - 32) × 5/975°F = 23.9°C

Optimal Temperature Ranges (°C and °F)

Growth StageCelsius (Day)Celsius (Night)Fahrenheit (Day)Fahrenheit (Night)
Clones/Seedlings20-25°C20-24°C68-77°F68-75°F
Vegetative22-28°C18-22°C72-82°F65-72°F
Early Flower20-26°C16-20°C68-79°F61-68°F
Late Flower18-24°C16-18°C65-75°F61-65°F
Drying15-18°C15-18°C60-65°F60-65°F
Curing15-21°C15-21°C60-70°F60-70°F

Solution Dilution Calculator

Dilution Formula

C₁V₁ = C₂V₂

  • C₁ = Initial concentration
  • V₁ = Initial volume
  • C₂ = Final concentration
  • V₂ = Final volume

Common Dilution Examples

Starting SolutionTarget ConcentrationCalculationDilution Required
10% bleach solution2% solution(10%)(V₁) = (2%)(1L)200 mL bleach + 800 mL water
70% isopropyl alcohol50% solution(70%)(V₁) = (50%)(1L)714 mL alcohol + 286 mL water
1000 ppm nutrient500 ppm(1000)(V₁) = (500)(10L)5L solution + 5L water
5.25% bleach (household)0.5% for sterilization(5.25%)(V₁) = (0.5%)(1L)95 mL bleach + 905 mL water

PPM Calculations for Nutrient Solutions

To prepare a solution with a specific ppm of an element:

  1. Determine the percentage of the element in your fertilizer
  2. Use the formula: grams of fertilizer = (desired ppm × liters of solution) ÷ (% element × 10)

Example: To make 5 liters of solution with 200 ppm nitrogen using a 20% nitrogen fertilizer: grams = (200 × 5) ÷ (20 × 10) = 5 grams

Growing Media Conversions

Soil Amendment Rates

AmendmentApplication RateVolume to WeightCoverage
Worm Castings5-20% by volume1 gallon ≈ 4 lbs (1.8 kg)1 ft³ covers 12 ft² at 1" depth
Perlite10-30% by volume1 gallon ≈ 1.5 lbs (0.7 kg)1 ft³ covers 12 ft² at 1" depth
Coco Coir10-100% by volume1 gallon ≈ 1.5 lbs (0.7 kg)1 ft³ covers 12 ft² at 1" depth
Compost20-30% by volume1 gallon ≈ 6 lbs (2.7 kg)1 ft³ covers 12 ft² at 1" depth

Media Weight to Volume Conversions

Growing Medium1 Cubic Foot Weighs1 Gallon Weighs
Peat moss (dry)7-9 lbs (3.2-4.1 kg)0.9-1.2 lbs (0.4-0.5 kg)
Coco coir (dry)10-12 lbs (4.5-5.4 kg)1.3-1.6 lbs (0.6-0.7 kg)
Perlite8 lbs (3.6 kg)1.1 lbs (0.5 kg)
Vermiculite7-10 lbs (3.2-4.5 kg)0.9-1.3 lbs (0.4-0.6 kg)
Potting soil30-40 lbs (13.6-18.1 kg)4-5.3 lbs (1.8-2.4 kg)
Garden soil40-50 lbs (18.1-22.7 kg)5.3-6.7 lbs (2.4-3.0 kg)

Media Moisture Capacity

Growing MediumWater Retention (volume %)Dry to Saturated Weight Increase
Peat moss60-75%8-10× dry weight
Coco coir80-90%8-9× dry weight
Perlite25-35%3-4× dry weight
Vermiculite40-50%4-5× dry weight
Potting soil30-45%2-3× dry weight
Garden soil20-30%1.5-2× dry weight
Rockwool80-90%15-20× dry weight

Note: Growing media weights and moisture capacities are approximate and may vary by brand, processing method, and compression.