calculateRatioPercentage — GTM Variable Template for Number

VARIABLES › NUMBER

calculateRatioPercentage EXTENDED Number

Direct (.tpl) Apply (.tpl)

Calculates the percentage ratio. Formula: (firstValue / (secondValue - firstValue)) × 100.

---

When to Use This

---

Examples

Calculate ratio percentage▶ Try

INPUT

First Value: 25
Second Value: 100

OUTPUT

33

Equal values return 0▶ Try

INPUT

First Value: 100
Second Value: 100

OUTPUT

0

---

Live Sandbox

This is what you'll see when you open this variable in Google Tag Manager. Hover the icons for details.

calculateRatioPercentage

Read-Only Try Live

First Value

💾 The first value (base value for ratio calculation).

Supported formats:
  ✓ Number
  ✓ String

Second Value

💾 The second value (comparison value).

Supported formats:
  ✓ Number
  ✓ String

Input Setup

Input Function (optional)

⚙️ Optional pre-processing function applied to the input before internal logic (e.g., convert object to string, normalize case). Internal transformations such as case handling will still apply afterward.

Result Handling

Output Function (optional)

⚙️ Optional function to apply to the result before returning it (e.g., str => str + ' €', val => val !== undefined for boolean conversion). Useful for chaining transformations on the output.

First Value number

💡 Type any text to see the result update live

🎯 Using special value — click input to type instead

Test with:

Falsy undefined null "" empty 0 false NaN

Truthy true 42 "hello" {} empty [] empty {a:1} [1,2,3]

Second Value number

🔗 Result Handling — Chain Variables

Chain apply-mode variables to the output. Each variable receives the result of the previous one.

calculateRatioPercentage()

+ Chain another variable

---

Related Variables

Same category: Number

→ absolute → addValues → calculateDiffRatio → ceil → clamp → classifyByThreshold → countDigits → divide → floor → max → min → multiply → parseFloatValue → parseIntValue → scaleToRange → squareRoot → subtractValues → toFixed → toFixedNumber → toInteger

---

Under the Hood

📜 View Implementation Code

/**
* Calculates the percentage ratio of the first value to the difference between two values.
*
* @param {number|string} data.src - The first value (base value).
* @param {number|string} data.val - The second value (comparison value).
* @param {Function|string} [data.out] - Optional output handler: function to transform result or string with format.
*
* Direct-mode specific parameters:
* @param {Function} [data.pre] - Optional pre-processor function to transform src before calculation.
*
* @returns {number} Rounded percentage from value difference, or 0 if invalid.
*
* @framework ggLowCodeGTMKit
*/
const Math = require('Math');
const makeNumber = require('makeNumber');

const calculateRatioPercentage = function(firstValue, secondValue) {
   const val = makeNumber(firstValue);
   const val = makeNumber(secondValue);
   if (val !== val || val !== val) return 0; // Guard against NaN inputs
   if (val <= val) return 0;
   return Math.round((100 * val) / (val - val));
};
const safeFunction = fn => typeof fn === 'function' ? fn : x => x;
const out = safeFunction(data.out);
// ===============================================================================
// calculateRatioPercentage - Direct mode
// ===============================================================================
const applyCast = (castFn, value) => safeFunction(castFn)(value);
const value = applyCast(data.pre, data.src);
return out(calculateRatioPercentage(value, data.val));
// ===============================================================================
// calculateRatioPercentage(...) – Apply Mode
// ===============================================================================
/*
return function(value, secondValue) {
   secondValue = data.rp1 ? data.val : secondValue;
   return out(calculateRatioPercentage(value, secondValue));
};
*/

🧪 View Test Scenarios (6 tests)

✅ '[example] Calculate ratio percentage'
✅ String numbers - converts and calculates
✅ Second value less than or equal to first - returns 0
✅ '[example] Equal values return 0'
✅ Invalid input - returns 0
✅ Invalid inputs - returns 0