Drawbar Power Calculator
A plough cutting 90 cm wide and 15 cm deep in soil with a specific draft of 7 N/cm², pulled at 4.5 km/h, needs 11.8125 kW at the drawbar.
Sandy soil 2–5, loam 4–8, clay 7–14 N/cm².
11.8125 kW
Full answer, then cut to fewer decimals (not rounded):
- 11.8125 kW
- 11.812 kW
- 11.81 kW
- 11.8 kW
- Draft
- 9.45 kN
- In horsepower
- 15.84082342 hp
- In metric horsepower
- 16.06053035 PS
Step-by-step solution
- Draft = specific draft × width × depth = 7 × 90 × 15 N = 9.45 kN
- DBP = draft × speed = 9.45 kN × 1.25 m/s = 11.8125 kW
Drawbar Power Formula
DBP = Draft × Speed
Draft = specific draft × width × depth; kW = kN × m/s
Worked Example
A plough cutting 90 cm × 15 cm in soil of 7 N/cm² specific draft at 4.5 km/h:
- Draft = specific draft × width × depth = 7 × 90 × 15 N = 9.45 kN
- DBP = draft × speed = 9.45 kN × 1.25 m/s = 11.8125 kW
In horsepower: 15.84082342 hp · In metric horsepower: 16.06053035 PS
GATE tip
Convert speed to m/s (÷ 3.6) before multiplying by draft in kN; the product is then in kW.
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Example: A tractor costing 8 lakh used 1000 h a year for 10 years: Total operating cost = 901.8 per hour.
Frequently asked questions
What is specific draft?
The draft per unit cross-section of soil cut, in N/cm²: about 2–5 for sandy soil and 7–14 for heavy clay.
How much engine power is needed?
Divide drawbar power by tractive efficiency and transmission efficiency, typically giving 1.5–2 times the drawbar power.
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures .
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Drawbar Power Calculator. Retrieved October 29, 2026, from https://scientificconverters.com/calculators/drawbar-power-calculator/
IEEE
Scientific Converters, "Drawbar Power Calculator," scientificconverters.com. Accessed: Oct. 29, 2026. [Online]. Available: https://scientificconverters.com/calculators/drawbar-power-calculator/