Calculating THC Dosage in Edibles: The Complete Math Guide
Precise dosing separates professional-quality edibles from guesswork. This guide provides formulas, examples, and tools to calculate exact THC content in any homemade cannabis product.
Precise dosing separates professional-quality edibles from guesswork. This guide provides formulas, examples, and tools to calculate exact THC content in any homemade cannabis product.
Quick Answer
Calculate THC dosage using: (grams of cannabis) x (THC% as decimal) x 1000 x (extraction efficiency) ÷ (number of servings) = mg THC per serving. Example: 10g at 20% THC with 80% efficiency, making 20 brownies = (10 x 0.20 x 1000 x 0.80) ÷ 20 = 80mg per brownie.
The Master Formula
Full Calculation
Total THC (mg) = Cannabis weight (g) x THC percentage x 1000 x Extraction efficiency
Per serving = Total THC ÷ Number of servings
Breaking It Down
Cannabis weight: Total grams used
THC percentage: Lab-tested percentage, or estimate (15-20% typical)
1000: Converts grams to milligrams
Extraction efficiency: How much THC transfers to your infusion (typically 0.7-0.9)
Step-by-Step Example
Scenario
Making cannabutter with 7 grams of 22% THC cannabis, then baking 24 cookies.
Step 1: Calculate Total THC
7 grams x 0.22 x 1000 = 1,540 mg THC in raw cannabis
Step 2: Apply Extraction Efficiency
For stovetop butter infusion, estimate 75% efficiency:
1,540 x 0.75 = 1,155 mg THC in finished butter
Step 3: Calculate Per-Cookie Dose
Using 1/2 cup of butter for recipe (half the batch):
1,155 ÷ 2 = 577.5 mg THC in cookie recipe
577.5 ÷ 24 cookies = 24 mg THC per cookie
Extraction Efficiency Reference
Fat-Based Infusions
| Method | Efficiency Range |
|---|---|
| Stovetop (butter) | 70-80% |
| Stovetop (coconut oil) | 75-85% |
| Slow cooker | 75-85% |
| Sous vide | 85-95% |
| Specialty machines | 80-90% |
Alcohol Tinctures
| Method | Efficiency Range |
|---|---|
| Traditional soak (2+ weeks) | 85-95% |
| Quick wash (QWET) | 70-80% |
| Everclear 190 proof | 90-95% |
| Everclear 151 proof | 80-90% |
Factors Affecting Efficiency
- Temperature: Optimal range maximizes extraction
- Time: Longer = more extraction (to a point)
- Agitation: Stirring improves contact
- Cannabis grind: Medium grind is ideal
- Fat saturation: Higher saturated fat binds better
Working Backwards: Target Dose Calculation
If You Want Specific Dose Per Serving
Cannabis needed = (Target dose x Servings) ÷ (THC% x 1000 x Efficiency)
Example: Want 10mg cookies, making 24
Target: 10mg x 24 = 240mg total THC needed
Using 20% THC cannabis with 80% efficiency:
240 ÷ (0.20 x 1000 x 0.80) = 240 ÷ 160 = 1.5 grams cannabis needed
Adjusting Existing Recipes
Making Recipe Stronger
Option 1: Use more cannabis in infusion
Option 2: Use more infusion in recipe (if recipe allows)
Option 3: Make fewer, larger portions
Making Recipe Weaker
Option 1: Mix infusion with regular fat (50/50 = half potency)
Option 2: Make more, smaller portions
Option 3: Use less cannabis initially
Unknown THC Percentage
When You Do Not Know Potency
Estimate based on quality:
- Low quality/trim: 8-12% THC
- Average flower: 15-18% THC
- Quality flower: 18-22% THC
- Premium flower: 22-28% THC
- Concentrates: 60-90% THC
Conservative Approach
When uncertain, use higher estimate (20%). This assumes stronger cannabis and results in lower-dose servings - safer than underestimating.
Concentrate Calculations
Distillate and Oils
Concentrates are typically 60-90% THC.
Example: 1 gram of 80% THC distillate
1 x 0.80 x 1000 = 800 mg THC
No extraction efficiency loss when adding to recipes directly.
Wax/Shatter
Slightly lower (60-80% typically). Decarb before using if not already activated.
Spreadsheet Formula
For Excel/Google Sheets
=(cannabis_grams * thc_percentage * 1000 * efficiency) / servings
Example:
- A1: Cannabis grams (10)
- A2: THC percentage (0.20)
- A3: Efficiency (0.80)
- A4: Servings (24)
- A5: Formula: =(A1A21000*A3)/A4
Result: 66.67 mg per serving
Common Scenarios Calculated
Scenario 1: Standard Brownie Batch
- 14g (1/2 oz) cannabis at 18% THC
- Stovetop butter infusion (75% efficiency)
- 16 brownies
Calculation: 14 x 0.18 x 1000 x 0.75 ÷ 16 = 118 mg per brownie
This is very strong. Cut into 32 pieces for ~59mg each.
Scenario 2: Mild Cookies
- 3.5g (1/8 oz) cannabis at 20% THC
- Slow cooker oil (80% efficiency)
- 24 cookies
Calculation: 3.5 x 0.20 x 1000 x 0.80 ÷ 24 = 23 mg per cookie
More reasonable dose.
Scenario 3: Micro-Dose Gummies
- Tincture containing 500mg THC total
- Making 50 gummies
Calculation: 500 ÷ 50 = 10 mg per gummy
Standard commercial-equivalent dose.
Accounting for Cooking Losses
Additional THC Degradation
Some THC degrades during cooking. Additional 10-20% loss is possible at high temperatures.
Conservative final calculation:
Calculated dose x 0.85 = realistic expectation
Minimizing Cooking Losses
- Bake at 325°F instead of 350°F
- Reduce cook time when possible
- Add infused ingredient near end of cooking when feasible
Testing Your Calculations
The Test Dose Method
Before consuming full serving:
- Calculate expected dose
- Consume 1/4 of that amount
- Wait 2 hours for full effects
- Evaluate accuracy
- Adjust calculations if needed
Keeping Records
Log each batch:
- Cannabis amount and source
- Assumed THC percentage
- Infusion method used
- Number of servings made
- Calculated dose per serving
- Actual effects experienced
This data improves future calculations.
Quick Reference Cheat Sheet
Cannabis to THC Quick Estimates (at 20% THC, 80% efficiency)
| Cannabis | Estimated THC Extracted |
|---|---|
| 1 gram | 160 mg |
| 3.5 grams (1/8 oz) | 560 mg |
| 7 grams (1/4 oz) | 1,120 mg |
| 14 grams (1/2 oz) | 2,240 mg |
| 28 grams (1 oz) | 4,480 mg |
Recommended Doses
| User Type | Per Serving |
|---|---|
| Beginner | 2.5-5 mg |
| Occasional | 5-15 mg |
| Regular | 15-30 mg |
| Experienced | 30-50+ mg |
Accurate dosing calculations transform cannabis cooking from guesswork to science. Use these formulas consistently for reliable, repeatable results.