To calculate Fuel Consumption for a 400 hp Gas engine with a BSFC of .50 lbs/hp/hr: 400 hp x .50 = 200 lbs/hr 3) Measure the diameter of your rear tire. So, to convert directly from mph to km/h (kph), you multiply by 1.6093439. Or, multiply by 0.44704/0.27777778 = 1.6093439. Engine Horsepower Calculator. If the distance was 300 kilometers and it took you 5 hours to cover it, your speed was 300 / 5 = 60 km/h (kilometers per hour). Multiply the value by 0.62. For any engine you can calculate the amount of fuel used, its thermal efficiency and its horsepower potential. For example, to convert from miles per hour to kilometers per hour you would multiply by 0.44704 then divide by 0.2777778. Calculate ET and MPH from HP and Weight: Next, let's look at an example showing the work and calculations that are involved in converting from feet per hour to miles per hour (ft/h to mph). Water Horsepower Calculator. This calculator computes the estimated engine or motor horsepower from elapsed time. Calculate the HP, Flow Rate or Discharge, and Total Head using this simple online calculator. Cubic Centimeters (CC). This calculator uses the following formulas: Calculate ¼-mile ET from HP and weight: ET and MPH in Quarter Calculator: ... Wallace Racing - ET/MPH/HP Calculator. Multiply the value by 1.6. A handy trick if you donât have a calculator to hand (e.g., you're driving) is to use the Fibonacci sequence (1, 1, 2, 3, 5, 8â¦). Enter the Weight and HP for ET and MPH, Then Press 'Enter' Key MPH = 234 * (HP / Weight) ^ .3333 ET = 1353 / MPH Weight Horsepower (no weather correction). Vehicle weight should include not only the vehicle, but also the driver, the passenger, and anything else of significant weight. The answers below will be for at sea level and standard pressure/temperature. Calculators to find 1/4 mile ET and MPH. The following two calculators can be used to estimate the engine horsepower of a vehicle based on the weight of the vehicle, elapsed time, and speed used to finish a quarter mile run. This rich Internet app uses the quarter mile distance or 400 meter track. Elapsed time is the duration a vehicle takes to complete a run in a competition. Expressed as a formula it looks like this: Given Horsepower x .50 lb fuel/hp = lbs of fuel for given horsepower. To convert from miles per hour to kilometres per hour: Take your speed. Diferent power units conversion from horsepower - Metric to Boiler horsepower. To convert kilometres per hour to miles per hour: Take your speed. I want to calculate: Flow Rate or Discharge(Q) = gpm Total Head(H) = ft Water Horsepower(WHP) = HP Calculator ; Formula ; Water Horsepower is the energy or power added to water by the pump. Try out this calculator get a rough estimate of horsepower. Standard Atmosphere. The Horsepower Calculator will calculate the horsepower of any vehicle instantly if you provide the total weight in pounds of the vehicle (and its occupants) and the MPH (miles per hour) that the vehicle is traveling the instant the vehicle crosses the finish line for the quarter mile (called the "trap speed"). 1 Horse power (33,000 Ft-lbs per minute) is the same as 42.4 BTUâs per minute or 2545 BTUâs per hour (33,000 /778 = 42.4165 x 60=2544.98). Weight is as the car sits on the line: driver and gas in it. To use the calculator, enter your air velocity or volume air flow and duct area/type, select your units, click calculate air flow and your converted velocity and volume. For example, a 2,400 pound vehicle with 300 horsepower should make it through the quarter-mile in 11.65 seconds, with a trap speed of 117.08 miles-per-hour. Said another way, we know for each horsepower our gas engine creates we will need .50 lbs of fuel per hour. If the total distance travelled was 500 miles and the time it took you was 5 hours, then your average speed was 500 / 5 = 100 miles per hour (mph).