Enter the 1/4 mile time, 1/8 mile time, and the conversion factor into the calculator to determine the missing variable. The default conversion factor is set to 1.57, which is commonly used in drag racing calculations.

1/4 ↔ 1/8 Mile ET
1/4 → 1/8
1/8 → 1/4
1/8 mile time

1/4 Mile to 1/8 Mile Time Formula

The following formula is used to calculate the 1/4 mile time from the 1/8 mile time and vice versa.

T_{1/4} = T_{1/8} \times CF

Variables:

  • ( T_{1/4} ) is the 1/4 mile time in seconds
  • ( T_{1/8} ) is the 1/8 mile time in seconds
  • ( CF ) is the conversion factor (default is 1.57)

To calculate the 1/4 mile time, multiply the 1/8 mile time by the conversion factor. Conversely, to calculate the 1/8 mile time, divide the 1/4 mile time by the conversion factor.

1/4 Mile to 1/8 Mile Time Conversion Table (Conversion Factor = 1.57)
1/4 Mile Time (s) 1/8 Mile Time (s)
74.459
85.096
95.732
106.369
117.006
127.643
12.57.962
138.280
13.58.599
148.917
14.59.236
159.554
15.59.873
1610.191
1710.828
1811.465
1912.102
2012.739
2214.013
2415.287
* Rounded to 3 decimals. Uses default factor: 1/8 mile time = 1/4 mile time ÷ 1.57.

What is a 1/4 Mile to 1/8 Mile Time Calculator?

A 1/4 mile to 1/8 mile time calculator is a tool used in drag racing to estimate the time it would take a vehicle to complete a 1/4 mile run based on its 1/8 mile time, or vice versa. This is particularly useful for racers who want to predict their performance over different distances without having to run the full length. The conversion factor used in the calculation is derived from empirical data and may vary slightly depending on the specific characteristics of the vehicle and track conditions.

How to Calculate 1/4 Mile to 1/8 Mile Time?

The following steps outline how to calculate the 1/4 mile to 1/8 mile time.


  1. First, determine the 1/4 mile time (( T_{1/4} )).
  2. Next, determine the 1/8 mile time (( T_{1/8} )).
  3. Next, determine the conversion factor (( CF )). The default value is 1.57.
  4. Finally, calculate the missing variable using the formula ( T_{1/4} = T_{1/8} times CF ) or ( T_{1/8} = T_{1/4} / CF ).
  5. After inserting the values and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

1/4 Mile Time (( T_{1/4} )) = 12.5 seconds

Conversion Factor (( CF )) = 1.57

Calculate the 1/8 Mile Time (( T_{1/8} )):