Ask a lawn care business owner how their business is doing and they'll almost always lead with the same number: revenue. A million dollars. Two million. Three.

Then ask if it's profitable. The answer is usually some version of "I think so" or "I'm not sure" or "the bank account looks about the same as it did last year."

Revenue without profit is just activity. And activity doesn't pay the bills, fund your retirement, or give you the freedom you started this business for in the first place.

The 40-40-20 rule exists to fix that — and once you understand it, you'll never look at your lawn care business financials the same way again.

The 40-40-20 rule is a simple framework for reading your profit and loss statement. It breaks your revenue into three categories and gives you a target for each:

40% — Cost of Goods Sold (COGS)
40% — Overhead Expenses
20% — Net Profit

That's it. If your P&L looks like this, you have a healthy, profitable lawn care business. If it doesn't, you know exactly which number to fix.

Cost of Goods: 40% or under
In a lawn care business, cost of goods is specifically field labor, field materials, disposal costs, and subcontractors. It does not include office expenses, insurance, trucks, or management salaries — those go in overhead.

The range you'll see in the industry is roughly 30–45%, depending on your service mix. Heavy mowing companies tend to run higher (up to 45%). Fertilization and weed control only companies can get this into the low thirties. If your COGS is above 45%, that's a red flag that needs immediate attention.

One real example: a client came in convinced his cost of goods was under control. When we pulled the actual number, it was 67%. He had no idea. That's the danger of gut-feel bookkeeping.

Overhead: 40% or under
Overhead covers everything else — your office, insurance, vehicles, equipment, management salaries, and your own compensation as the owner. Keep it at or under 40% and you have room to hit the number that really matters.

Net Profit: 20%
This is the goal. Twenty percent net profit, taken to the bank, every year. Not 5%. Not breaking even. Twenty percent.
Dentists hit it. Attorneys hit it. There's no reason a well-run lawn care business can't hit it too — but it never happens by accident. It only happens when you're intentional, meticulous, and committed to understanding your numbers.

You cannot use the 40-40-20 rule if your books are a mess. If your cost of goods line includes shop supplies, truck payments, and random purchases from the owner — you'll never get an accurate picture of your business health.

Clean books means your P&L is balanced to the penny every single month. Your COGS line contains only what it should contain. Your overhead is separated cleanly. And your net profit number reflects reality — not wishful thinking.

That's not something most general bookkeepers set up correctly. They use a generic QuickBooks template built for a restaurant or a retail store — not a lawn care operation. Getting your chart of accounts set up specifically for this industry is step one.

The most common failure point is pricing. When cost of goods runs high, it's usually because the work is being underpriced — not because the business owner is careless, but because they never had the right data to know what to charge.

Here's a quick example: a lawn care owner quotes an irrigation job at $250. Labor alone — two guys, four hours — is going to cost him close to $200 before materials. He's not breaking even, let alone hitting 40-40-20. He just didn't know it until someone showed him the math.

Once you know your numbers, you can price every job with confidence — because you know exactly what you need to charge to keep your COGS where it belongs.

The 40-40-20 rule only works with accurate, monthly bookkeeping built specifically for a lawn care business. If you're currently working off bank balance guesses or a P&L that hasn't been touched in months, you're making one of the most expensive mistakes a business owner can make.

At Lawn Care Books, we set up your books the right way from day one — lawn care-specific chart of accounts, monthly P&L reconciled to the penny, and reporting that makes the 40-40-20 rule actionable every single month.

Want to know where your business stands right now? Book a free 15-minute discovery call and we'll look at your numbers together — no pressure, no pitch, just clarity.