How to calculate percentage between the range of two values a third value is

Question

Example:

I'm trying to figure out the calculation for finding the percentage between two values that a third value is.

Example: The range is 46 to 195. The value 46 would 0%, and the value 195 would be 100% of the range. What percentage of this range is the value 65?

rangeMin=46

rangeMax=195

inputValue=65

inputPercentage = ?

inputPercentage = (inputValue/(rangeMax-rangeMin))*100 <-- this isn't working — user45675, Sep 14 '14 at 16:51
If the range from 46 to 195 is supposed to be 100%, then you have to _subtract_ 46 from 195 to “normalize” that range; and then the same for the value 65 … and after that, it’s just “normal” percentage calculation. — CBroe, Sep 14 '14 at 16:53

score 313 · Accepted Answer · edited Mar 15 '20 at 00:17

313

Well, I would use the formula

((input - min) * 100) / (max - min)

For your example it would be

((65 - 46) * 100) / (195 - 46) = 12.75

Or a little bit longer

range = max - min
correctedStartValue = input - min
percentage = (correctedStartValue * 100) / range

If you already have the percentage and you're looking for the "input value" in a given range, then you can use the adjusted formula provided by Dustin in the comments:

value = (percentage * (max - min) / 100) + min

edited Mar 15 '20 at 00:17

Community

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1

answered Sep 14 '14 at 16:54

Tom

16,842
17
45
54

30

I needed to find the value in a range given the percentage. Taking this formula, I reworked it to `val = ((percent * (max - min) / 100) + min` – Dustin Feb 17 '16 at 23:11
1

I suspect the formula can work when either one or both the range numbers are negative. – Kaizar Laxmidhar Feb 24 '17 at 14:36
How would this work if the range has a negative number in either max or min? – Daisy Jul 02 '19 at 20:36
@Daisy, well let's test it. If you're going from -10 to 10, then range is `10 - (-10)` which is `10 + 10` and 20. Looks correct. Then assume input is 8. `correctedStartValue` would be `8 - (-10)` = 18. That first looks strange, but lets keep going. The result would be `(18*100) / 20` = 90%. And 90% looks fine to me for value 8 between -10 and 10. – Tom Jul 02 '19 at 20:46
@Daisy You only need to make sure that when both values are below 0, then max is the value with the largest absolute value. For example -50 and -20, then max=-50 and min=-20. Range will be -30, but that is fine. The negative sign is needed, since `correctedStartValue` will be negative as well. – Tom Jul 02 '19 at 20:48

Daniel Tonon · Answer 2 · 2016-02-10T03:39:57.543

I put together this function to calculate it. It also gives the ability to set a mid way 100% point that then goes back down.

Usage

//[] = optional
rangePercentage(input, minimum_range, maximum_normal_range, [maximum_upper_range]);

rangePercentage(250, 0, 500); //returns 50 (as in 50%)

rangePercentage(100, 0, 200, 400); //returns 50
rangePercentage(200, 0, 200, 400); //returns 100 
rangePercentage(300, 0, 200, 400); //returns 50

The function

function rangePercentage (input, range_min, range_max, range_2ndMax){

    var percentage = ((input - range_min) * 100) / (range_max - range_min);

    if (percentage > 100) {

        if (typeof range_2ndMax !== 'undefined'){
            percentage = ((range_2ndMax - input) * 100) / (range_2ndMax - range_max);
            if (percentage < 0) {
                percentage = 0;
            }
        } else {
            percentage = 100;
        }

    } else if (percentage < 0){
        percentage = 0;
    }

    return percentage;
}

score 1 · Answer 3 · answered Dec 14 '17 at 11:55

If you want to calculate the percentages of a list of values and truncate the values between a max and min you can do something like this:

private getPercentages(arr:number[], min:number=0, max:number=100): number[] {
  let maxValue = Math.max( ...arr );

  return arr.map((el)=>{
    let percent = el * 100 / maxValue;
    return percent * ((max - min) / 100) + min;
  });
};

Here the function call:

this.getPercentages([20,30,80,200],20,50);

would return

[23, 24.5, 32, 50]

where the percentages are relative and placed between the min and max value.

score 0 · Answer 4 · edited Oct 24 '19 at 08:58

Can be used for scaling any number of variables

Python Implementation:

# List1 will contain all the variables
list1 = []
# append all the variables in list1
list1.append(var1)
list1.append(var2)
list1.append(var3)
list1.append(var4)


# Sorting the list in ascending order
list1.sort(key = None, reverse = False)

# Normalizing each variable using ( X_Normalized = (X - X_minimum) / (X_Maximum - X_minimum)  )
normalized_var1 = (var1 - list1[0]) / (list1[-1] - list1[0])
normalized_var2 = (var2 - list1[0]) / (list1[-1] - list1[0])
normalized_var3 = (var3 - list1[0]) / (list1[-1] - list1[0])
normalized_var4 = (var4 - list1[0]) / (list1[-1] - list1[0])

How to calculate percentage between the range of two values a third value is

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