Here’s the math behind the calculations used in the Lawn Mowing Calculator that helps you determine the amount of time it will take to complete mow, trim, and blow services for a yard based on lawn size, obstacles, and the mowing equipment you’re using. 

Select Mower Type and Speed to Determine Coverage Rate:

The calculator uses typical coverage rates per hour based on mower type and speed:

• Push Mower (3 MPH): ~27,720 sq ft per hour
• Riding Lawn Mower (4 MPH): 60,676 – 101,112 sq ft per hour
• Residential Zero-Turn (6.5 MPH): 118,800 – 190,080 sq ft per hour
• Commercial Zero-Turn (10 MPH): 184,800 – 343,200 sq ft per hour

These rates help the calculator estimate the time required to mow the yard, adjusted to lawn size.

Convert Mower Speed to Feet per Minute:

The calculator converts speed in MPH to feet per minute:

Speed (ft/min)=Speed (MPH)×88\text{Speed (ft/min)} = \text{Speed (MPH)} \times 88

Speed (ft/min)=Speed (MPH)×88

This allows for a tailored estimation of mowing time based on mower efficiency.

Include Cutting Width:

Cutting width is multiplied with speed (in ft/min) and mowing time (in minutes) to determine area coverage:

Area Covered per Hour (sq ft)=Speed (ft/min)×Cutting Width (ft)×60\text{Area Covered per Hour (sq ft)} = \text{Speed (ft/min)} \times \text{Cutting Width (ft)} \times 60

Area Covered per Hour (sq ft)=Speed (ft/min)×Cutting Width (ft)×60

Estimate Mowing Time with Yard Size:

• • Based on the lawn size, the calculator uses the selected mower’s hourly coverage rate to give a Time to Mow Only estimate, which reflects typical mowing under standard conditions.

Adjust for Lawn Conditions and Obstacles:

Additional time adjustments are made for job complexity:

• • • Trees (1 min per tree)
    • Parkway, Flower Beds, Fence Line (5 min per 2,500 sq ft)
    • Overgrown Grass (5 min per 1,000 sq ft)
    • Other Factors (slopes, wet grass, pet waste, etc.)

This ensures realistic time calculations, factoring in trimming and navigation around obstacles.

This lawn has a steep incline in the backyard that takes additional time to trim.

Blower Type and Trimming Time:

• • Blower type affects trim and blow timing:
    • BackPack Blower (3 min per 1,000 sq ft)
    • Handheld Blower (10 min per 1,000 sq ft)

Crew Size Adjustment:

• • Crew size impacts job speed, so the calculator reduces time as follows:
    • 1 crew = no reduction
    • 2 crew = 45% time reduction
    • 3 crew = 65% time reduction
    • 4 crew = 75% time reduction

Note: Be sure to adjust your desired hourly rate based on the crew size to ensure profitability. A good rule of thumb is to generate 3x the hourly rate for each crew member to cover wages and still turn a profit.