Cleaning robot or floor scrubber: how to compare the costs?

“A robot costs more than a floor scrubber.” That's true at purchase, but it's not the right comparison. What a robot mostly replaces is labour time, every day, for years. Here is the method we use in our project calculator.

Step 1: how is it done today?

Under about 20,000 sq ft, cleaning is usually done with a mop and broom. We count a pace of about 5,000 sq ft per hour for one person.

From 20,000 sq ft, a person normally uses manual equipment:

• a walk-behind scrubber or sweeper, typically $5,000 to $10,000;
• a ride-on scrubber for very large areas, typically $15,000 to $20,000.

In that case, we assume the person moves at the same pace as the robot they replace, and we count the price of the machine: it's a purchase the robot saves you.

Step 2: the monthly cost of manual cleaning

Labour per month = hours per cleaning × cleanings per month × hourly rate. Example: 25,000 sq ft of hard floor scrubbed five times a week. At the pace of the robot that would do the job, a Carl CC1 Pro, that's about 2.6 hours per cleaning and 21.7 cleanings per month; at $30 an hour, about $1,700 of labour per month. Add the walk-behind scrubber, amortized over five years: $125 per month.

Step 3: the monthly cost of the robot

The robot cleans autonomously: we count no labour on its side. Its price is spread over 60 months, like the manual machine's, so we compare like-for-like monthly amounts.

Step 4: savings, payback and ROI

• Monthly savings = monthly cost of manual cleaning − monthly robot cost
• Payback period = (monthly robot cost − avoided machine amortization) × 60 ÷ monthly labour
• Net 5-year ROI = monthly savings ÷ monthly robot cost

In our 25,000 sq ft example, the robot pays for itself in about 15 months and the net five-year ROI is above 200%.

What the calculation leaves out

Some benefits are harder to put a number on, but our customers tell us about them:

• more frequent cleaning and better overall cleanliness;
• less staff management;
• no water waste;
• consumable costs equivalent to a traditional machine;
• monitoring reports always available;
• an image of quality and innovation for your building.

Run the numbers for your site

Our calculator applies this method to your floor area, frequency and hourly rate, and can email you the detailed analysis. To validate the figures against your real constraints, book a free consultation.