THC/CBD Ratio Calculator

ANA›Life Services Authority›National Calculator Authority›THC/CBD Ratio Calculator

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THC/CBD Ratio Calculator

Enter the THC and CBD percentages (or mg) from your cannabis product label to calculate the ratio and understand its likely effects profile.

THC Amount

CBD Amount

Unit

Percent (%) Milligrams (mg)

Calculate

function thcCalc() { var thcVal = parseFloat(document.getElementById('thc-thc-amount').value); var cbdVal = parseFloat(document.getElementById('thc-cbd-amount').value); var unit = document.getElementById('thc-unit').value; var resultDiv = document.getElementById('thc-result');

// --- Validation --- if (isNaN(thcVal) || isNaN(cbdVal)) { resultDiv.style.display = 'block'; resultDiv.innerHTML = '⚠ Please enter valid numbers for both THC and CBD.'; return; } if (thcVal ⚠ Values cannot be negative.'; return; } if (unit === 'percent' && (thcVal > 100 || cbdVal > 100)) { resultDiv.style.display = 'block'; resultDiv.innerHTML = '⚠ Percentage values cannot exceed 100%.'; return; } if (unit === 'percent' && (thcVal + cbdVal) > 100) { resultDiv.style.display = 'block'; resultDiv.innerHTML = '⚠ Combined THC + CBD cannot exceed 100%.'; return; } if (thcVal === 0 && cbdVal === 0) { resultDiv.style.display = 'block'; resultDiv.innerHTML = '⚠ Both values are zero. Please enter at least one non-zero value.'; return; }

// --- Core Calculations --- var unitLabel = (unit === 'percent') ? '%' : ' mg';

// Ratio expressed as THC : CBD var ratioTHC, ratioCBD, ratioStr, dominanceStr, profileStr, profileColor;

if (cbdVal === 0) { ratioStr = 'THC Only (No CBD)'; dominanceStr = 'Pure THC'; profileStr = 'Highly psychoactive; no CBD modulation present.'; profileColor = '#c0392b'; ratioTHC = null; ratioCBD = null; } else if (thcVal === 0) { ratioStr = 'CBD Only (No THC)'; dominanceStr = 'Pure CBD'; profileStr = 'Non-psychoactive; CBD-dominant product.'; profileColor = '#27ae60'; ratioTHC = null; ratioCBD = null; } else { // Simplify ratio by dividing both by GCD (using decimal GCD via scaling) var scale = 100; var thcInt = Math.round(thcVal * scale); var cbdInt = Math.round(cbdVal * scale);

function gcd(a, b) { return b === 0 ? a : gcd(b, a % b); } var g = gcd(thcInt, cbdInt); ratioTHC = thcInt / g; ratioCBD = cbdInt / g;

// Simplify further if ratio numbers are large — express as decimal ratio var rawRatio = thcVal / cbdVal; // THC per 1 CBD if (ratioTHC > 50 || ratioCBD > 50) { ratioStr = rawRatio.toFixed(2) + ' : 1 (THC : CBD)'; } else { ratioStr = ratioTHC + ' : ' + ratioCBD + ' (THC : CBD)'; }

// Dominance classification if (rawRatio >= 10) { dominanceStr = 'High THC Dominant'; profileStr = 'Strong psychoactive effects; minimal CBD modulation. Suitable for experienced users.'; profileColor = '#c0392b'; } else if (rawRatio >= 4) { dominanceStr = 'Moderate THC Dominant'; profileStr = 'Psychoactive with some CBD balance. Common in recreational products.'; profileColor = '#e67e22'; } else if (rawRatio >= 2) { dominanceStr = 'Mild THC Dominant'; profileStr = 'Moderate psychoactivity; CBD begins to temper THC effects.'; profileColor = '#f39c12'; } else if (rawRatio > 0.5 && rawRatio = 0.1) { dominanceStr = 'CBD Dominant'; profileStr = 'Low psychoactivity; CBD effects predominate. Common in therapeutic products.'; profileColor = '#27ae60'; } else { dominanceStr = 'High CBD Dominant'; profileStr = 'Minimal to no psychoactivity; primarily CBD-driven effects.'; profileColor = '#1abc9c'; } }

// Total cannabinoid content var total = thcVal + cbdVal;

// CBD modulation index: CBD / (THC + CBD) * 100 var modulationIndex = (total > 0) ? (cbdVal / total * 100) : 0;

// THC equivalent (accounting for CBD modulation — simplified Russo model)
// Effective THC potency is reduced when CBD is present
// Approximate: effective THC = THC * (1 - 0.5 * (CBD / (THC + CBD)))
var effectiveTHC = (thcVal > 0 && cbdVal > 0)
? thcVal * (1 - 0.5 * (cbdVal / total))
thcVal;

// --- Build Output --- var html = '### Results '; html += '';

function row(label, value, color) { return '' + '' + label + '' + '' + value + '' + ''; }

html += row('THC Amount', thcVal.toFixed(2) + unitLabel); html += row('CBD Amount', cbdVal.toFixed(2) + unitLabel); html += row('Total Cannabinoids', total.toFixed(2) + unitLabel); html += row('THC : CBD Ratio', ratioStr, profileColor); html += row('Dominance Profile', dominanceStr, profileColor); html += row('CBD Modulation Index', modulationIndex.toFixed(1) + '% of total cannabinoids is CBD'); if (thcVal > 0 && cbdVal > 0) { html += row('Estimated Effective THC', effectiveTHC.toFixed(2) + unitLabel + ' (CBD-modulated)'); }

html += '';

html += '' + 'Effects Profile: ' + profileStr + '';

resultDiv.style.display = 'block'; resultDiv.innerHTML = html; }

#### Formulas Used

THC : CBD Ratio — Divide both values by their Greatest Common Divisor (GCD) to express the simplest whole-number ratio:

Ratio = (THC / GCD) : (CBD / GCD)

CBD Modulation Index — The proportion of total cannabinoids that is CBD:

Modulation Index (%) = CBD / (THC + CBD) × 100

Estimated Effective THC — A simplified model (based on Russo's entourage effect research) estimating how CBD attenuates perceived THC potency:

Effective THC = THC × (1 − 0.5 × (CBD / (THC + CBD)))

The 0.5 coefficient reflects that CBD partially (not fully) antagonises THC at CB1 receptors.

#### Assumptions & References

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References

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