Tool Cost Per Use: The Math Behind Buy vs Borrow
FriendsWithTools.io earns a commission from qualifying purchases made through links on this page, at no additional cost to you. We do not test these tools ourselves — all claims are sourced from manufacturer specifications, retailer listings, and aggregated user reviews, each linked inline. Prices and ratings were verified on May 2026 and may have changed.
A $400 pressure washer used twice a year costs $200 per use. A $50 cordless drill used twice a week costs $0.48 per use after one year. The math makes the buy-vs-borrow decision obvious for most tools, but people skip the math and buy everything. This guide runs the numbers on common tools so you can see exactly where the break-even points fall.
How to Calculate Cost Per Use
The formula is straightforward: (purchase price + lifetime maintenance cost) divided by total uses over the tool's lifespan. A $200 miter saw with $50 in blade replacements over 10 years, used 30 times per year, costs ($200 + $50) / 300 = $0.83 per use. That is less than a cup of coffee for a tool that makes precise angled cuts in hardwood.
Compare that to the rental alternative: the same miter saw rents for $40 to $60 per day at most home improvement stores. At 30 uses per year (roughly one use every other weekend), renting would cost $1,200 to $1,800 per year. Buying pays for itself after the second or third rental. Borrowing from a friend or neighbor costs $0 per use plus a few minutes of coordination.
The break-even point is the number of uses where buying becomes cheaper than the alternative. For renting, the break-even is usually 3 to 5 uses, depending on the tool's purchase price and rental rate. For borrowing (free), buying is always more expensive per use in pure dollar terms. The real comparison against borrowing is the logistical cost: is coordinating the borrow worth the savings, or is immediate access from your own shelf worth the purchase price?
The hidden costs that people forget: storage space (every tool takes room in a garage, closet, or shed), maintenance (gas-powered tools need winterizing, battery tools need periodic charging to preserve cell health, blades and bits need replacing), and depreciation (a $400 tool is typically worth $100 to $150 after 5 years on the used market). These factors do not dramatically change the math for most tools, but they tip the scale toward borrowing for large, infrequently used equipment that takes up significant storage space.
Tools That Pay for Themselves Fast
These are the tools where buying is the clear winner. High frequency of use, low purchase price relative to rental cost, and broad applicability across many project types.
Cordless drill/driver ($80 to $150). Used 50 to 200+ times per year by active homeowners (hanging shelves, assembling furniture, driving screws, drilling pilot holes). Cost per use after year one: under $1 for the $80 models, under $3 even for a $150 kit used only 50 times. Break-even vs rental: 2 uses, since rental runs $30 to $50 per day. Verdict: buy it. This is the highest-value tool purchase any homeowner can make. Cordless drill guide.
Circular saw ($80 to $200). Used 10 to 50 times per year for homeowners who do any woodworking, deck work, or renovation. Cost per use after 3 years: $1 to $4, depending on purchase price and frequency. Break-even vs rental: 3 to 4 uses (rental is $30 to $50/day). Verdict: buy if you do any regular woodworking or home improvement. Borrow if you need it for a single afternoon. Circular saw guide.
Impact driver ($80 to $150). Used alongside the drill for driving screws, especially long screws into dense material. The impact mechanism delivers high rotational torque without straining your wrist. Cost per use drops below $1 within the first year for anyone doing deck, fence, or framing work. Verdict: buy as soon as you take on your first structural project. Before that, your drill handles most driving tasks.
Basic hand tool set ($50 to $100 total). Hammer, screwdrivers, pliers, adjustable wrench, tape measure. Used hundreds of times per year collectively. Cost per use: fractions of a cent after the first year. These tools last decades with zero maintenance. They are never worth borrowing because the coordination time exceeds the replacement cost. Buy them once.
Shop vacuum ($60 to $150). Used after every project for cleanup, plus car interior cleaning, garage sweeping, and water extraction from minor floods or appliance leaks. Cost per use: under $1 after year one for a model used twice a week. The filter replacement ($10 to $15 annually) is the only ongoing cost. Verdict: buy. A shop vac is a utility tool, not a specialty one. Workshop organization guide.
Tools Where Borrowing Wins
These tools are expensive, bulky, and used infrequently by most homeowners. The cost per use stays high for years because the denominator (number of uses) grows slowly.
Pressure washer ($300 to $800 gas, $100 to $250 electric). Used 2 to 4 times per year for driveway, deck, siding, and patio cleaning. Cost per use after 5 years: $15 to $40 for a gas model, $5 to $12 for electric. Rental runs $50 to $75 per day. Gas models also require fuel, oil changes, and winterizing with fuel stabilizer ($5 to $10/year in consumables). Verdict: borrow. A neighbor with a pressure washer will typically lend it for a Saturday. One machine can easily serve an entire block if everyone takes turns. Most-borrowed tools guide.
Drywall lift ($200 to $400). Used for exactly one purpose: holding full sheets of drywall against a ceiling while you screw them in. Most homeowners need this for a single project and then never again. Cost per use: the full purchase price if you use it once. Rental: $40 to $60 per day. Verdict: borrow or rent. Buying a drywall lift for one ceiling job is one of the worst cost-per-use ratios in home improvement.
Tile wet saw ($250 to $600). Used for 2 to 5 days per bathroom or kitchen tile project. Cost per use: $50 to $120+ if you tile one room and stop. Rental: $50 per day at most home improvement stores. Verdict: borrow for a single project. If you plan to tile multiple rooms over the next few years, the $100 to $150 entry-level models (like the QEP 7-inch) bring the cost per use down to a reasonable range. Tile tools overview.
Concrete mixer ($250 to $500). Used for 1 to 2 days per project (fence post footings, small pads, repair work). Weighs over 100 pounds. Storage: takes half a garage bay. Verdict: borrow or rent. Unless you pour concrete multiple times per year (contractor territory), this tool sits idle taking up valuable space.
Powered lawn aerator ($300 to $2,000+). Used once per year, typically in fall. Rental: $80 to $100 per day. Verdict: borrow. This is the single most-borrowed tool in suburban tool-sharing groups, according to usage data from community lending libraries. Everyone needs it during the same 4-week window in autumn, so coordinating the borrow schedule is the main challenge.
Airless paint sprayer ($300 to $1,000). Used 1 to 3 times per year for most homeowners (exterior painting, fence staining, large interior rooms). Cleanup takes 30 to 45 minutes per use, which is a cost in time even if the tool itself is free to borrow. Verdict: borrow for the one big exterior job. The cleanup burden alone is a reason many homeowners prefer to not own one.
The Gray Zone
These tools fall between the obvious buy and obvious borrow categories. The right answer depends on your specific project frequency and how much you value immediate access vs saving money.
Miter saw ($200 to $500). Used 5 to 20 times per year by active renovators who install their own trim, baseboards, and crown molding. Cost per use after 5 years: $2 to $10. If you install trim in 2 to 3 rooms, a miter saw pays for itself compared to renting. If you do one room every few years, borrowing is the better path. The miter saw is the tool that most often graduates from "borrow" to "own" after the third or fourth borrow. Miter saw guide.
Random orbit sander ($50 to $130). Used 10 to 30 times per year by woodworkers and furniture refinishers, 3 to 5 times per year by general homeowners. Cost per use: $2 to $25, depending on frequency. At the lower end of the price range ($50 to $60), buying is easy to justify even for occasional use. At the higher end, the decision depends on how many sanding projects you actually complete in a year. Sandpaper disc refills add $10 to $20 per year to the operating cost. Sander guide.
Oscillating multi-tool ($80 to $200). Used 5 to 15 times per year. The multi-tool is most useful when you do not expect to need it: a surprise door-jamb cut during flooring installation, unexpected grout removal, stubborn caulk that will not come off with a utility knife. If you have borrowed one three times, buying your own for instant access starts to make sense. The convenience value of having it on your shelf exceeds the dollar cost for active DIYers.
Router ($100 to $300 for a combo kit). Used 5 to 50 times per year, depending heavily on whether you do woodworking. For a dedicated woodworker who rounds edges, cuts dadoes, and routes decorative profiles regularly: buy, without question. For a general homeowner who needs a router for one specific project: borrow. The learning curve on a router is steeper than most tools, so borrowing also lets you try before committing. Woodworking tools guide.
The Tool-Sharing Advantage
The cost-per-use math above assumes two options: buy at full price or rent by the day. Borrowing through a tool-sharing network introduces a third option that changes the equation for every tool in the gray zone and the borrow-wins category.
A tool that costs $300 and gets used 4 times per year by one owner can be used 12+ times per year across three neighbors. The effective cost per use drops to one-third. The tool earns its keep. The owner does not mind lending because the tool is being used instead of collecting dust and depreciating in a garage corner.
The economics of tool sharing favor tools that meet four criteria: expensive (over $200 purchase price), used infrequently (under 10 times per year per household), durable (can survive lending without damage), and commonly needed (every homeowner needs them at some point). This description fits most power tools and virtually all specialty equipment.
The tools that do not benefit from sharing are the ones you use daily (your personal drill, your everyday tape measure) and consumable items (sandpaper, drill bits, saw blades). Everything else is a sharing candidate. FriendsWithTools makes the coordination simple: list what you own, see what your neighbors have, and schedule borrows without the awkward text-message back-and-forth.
Frequently Asked Questions
What About Depreciation?
Power tools lose about 50% of their value in the first 2 years and then depreciate more slowly after that. Based on resale data from used tool marketplaces, a $200 tool is worth about $80 to $100 after 2 years and $50 to $70 after 5 years if well-maintained. For the cost-per-use calculation, depreciation matters most for expensive tools used rarely. A $600 table saw that depreciates to $300 in 2 years "costs" $150 per year in depreciation alone, even if you never turn it on. For frequently used tools under $200, depreciation is a rounding error in the total cost of ownership.
Does Battery Degradation Change the Math for Cordless Tools?
Yes, but not enough to change the buy/borrow verdict for most tools. Lithium-ion batteries lose capacity over time: manufacturer data and user reports indicate 70% to 80% of original capacity remaining after 3 to 5 years of regular use. A replacement battery costs $50 to $120 depending on the platform and amp-hour rating. Factor one battery replacement into the total cost of ownership for any cordless tool you plan to keep long-term. This does not change the "buy" verdict for high-use tools like drills and impact drivers, but it does add $10 to $25 per year to the true cost per use for tools used less frequently. Battery care guide.