Rent vs. Buy: A Simple Calculator That Shows When Borrowing From a Neighbor Always Wins

Most people never do the math. They see something they need, they buy it, and it moves from the store shelf to the garage shelf — where it sits for years earning nothing and costing floor space. For a huge category of items, renting from a neighbor is the objectively smarter financial move. Not just a little smarter. Dramatically smarter. Here's how to know which side of the line you're on.

The Simple Formula: Break-Even Math

Break-even uses = Buy cost ÷ Daily rental rate

If you'll use the item fewer times than the break-even number — renting wins.

• Pressure Washer — $350 to buy / $35/day → break-even: 10 uses. Most people use it 2–3x/year → renting wins by year 3–5.
• Ladder — $120 to buy / $15/day → break-even: 8 uses. Even if the numbers come out even, the storage argument tilts it toward renting.
• Camera / DSLR — $800 to buy / $50/day → break-even: 16 uses. At 3–5 uses/year that's 3–5 years, and by then the body is two generations behind.
• Bounce House — $400 to buy / $75/day → break-even: 5.3 uses. At 1–2 birthday parties/year, renting wins indefinitely.
• Power Drill — $80 to buy / $20/day → break-even: 4 uses. Active DIYers hit that in a month. Buying wins.

Summary Table

Hidden Costs Nobody Counts

Storage space, depreciation (15–20%/year), maintenance, and hose/battery degradation. A $350 pressure washer over 10 years is closer to $500–$600 in real cost once you count garage real estate and upkeep.

When Buying Actually Makes Sense

Use it 15+ times/year? Buy it. Contractors, daily-use tools, small cheap durables — ownership wins. For everything else: rent.