# How to calculate value of a percent of a range

Hi I have a range and percent of that range. I want to calculate the value of that percentage.

for exam:

min = -5
max = 30
percentage = 8%

value = ?


Value should be a 8% of the range of (-5 .. 30)

• The question is all but trivial since percentage is a linear function of the value given the range. Have you tried to solve for it? – Saad Jan 8 '18 at 5:31
• I don't know math and yes I tried ! – Vahid Jan 8 '18 at 5:32
• Calculate the $8\%$ point of the range $[0,35]$ then shift it down by $5$. – dxiv Jan 8 '18 at 5:34

Since$$\text{percentage} = \frac{\text{value} - \min}{\max - \min} \times 100\%,$$ then$$\text{value} = \min + (\max - \min) \times \text{percentage}.$$
Find $8\%$ of $30-(-5)$. That is $$\frac{8}{100}\times 35=m.$$ Then what you want is $-5+m$.