The fraction 30/80 is equivalent to 37.5 percent or 37.5% (rounded to 1 decimal place).
To workout this, divide the numerator by the denominator, sum this value to the integer part then multiply the result by 100%, so:
30/80 in percent = 30 ÷ 80 × 100% =
0.375 × 100% =
37.5%