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.

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.

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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)

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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

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Extraction Efficiency Reference

Fat-Based Infusions

Alcohol Tinctures

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

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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

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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

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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.

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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.

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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: =(A1A21000A3)/A4

Result: 66.67 mg per serving

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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.

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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

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Testing Your Calculations

The Test Dose Method

Before consuming full serving:

1. Calculate expected dose

2. Consume 1/4 of that amount

3. Wait 2 hours for full effects

4. Evaluate accuracy

5. 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.

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Quick Reference Cheat Sheet

Cannabis to THC Quick Estimates (at 20% THC, 80% efficiency)

Recommended Doses

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Accurate dosing calculations transform cannabis cooking from guesswork to science. Use these formulas consistently for reliable, repeatable results.