Fix or replace? Count the years left, not the repair bill
Fix It or Not, AI-assisted writing ยท
Overview
The popular rule says to repair an appliance when the repair costs less than half the price of a new one [3]. It is easy to remember and it ignores the one thing that decides the answer: how many years the repaired machine has left. This entry puts the years back in, using the average lifespans from a survey of manufacturers and researchers [2], and works through examples where the rule and the arithmetic disagree.
How long appliances last
The figures most often quoted come from a survey the US National Association of Home Builders ran in 2006 with manufacturers, trade associations and researchers, published in 2007 [2]:
| Appliance | Average life |
|---|---|
| Gas range | 15 years |
| Standard refrigerator, electric range, dryer | 13 years |
| Food waste disposer | 12 years |
| Freezer | 11 years |
| Washer | 10 years |
| Dishwasher, microwave oven, compact refrigerator | 9 years |
They are averages from a survey, not guarantees: installation, maintenance and how hard a machine works all move them [2]. Use them as the starting point and adjust for what you know about yours.
The rule that counts the years
Compare two prices per year. A repair costs its price divided by the years it buys, roughly the average life minus the machine's age. A new machine costs its price divided by its whole life. Fix when the first is lower [1].
The examples below show how often the 50% rule and the years disagree. All prices are examples in any currency [1]:
| Example | Repair per year left | New per year of life | The years say | The 50% rule says |
|---|---|---|---|---|
| Dishwasher, 7 years old, repair 150, new 600 | 75 | 67 | replace | fix |
| Washer, 8 years old, repair 200, new 700 | 100 | 70 | replace | fix |
| Refrigerator, 4 years old, repair 250, new 900 | 28 | 69 | fix | fix |
| Dryer, 3 years old, repair 400, new 700 | 40 | 54 | fix | replace |
The rule fails in both directions. It tells you to pour money into an old machine near the end of its life, and to throw away a young one that a large repair would keep going for a decade [1].
The break-even repair is worth knowing before you ask for a quote: for the 7-year-old dishwasher it is about 133, and for the 4-year-old refrigerator about 623 [1]. Anything below that is worth fixing.
Nerd corner
Fix when R / max(L − a, 1) < N / L, with R the repair, L the average life, a the age and N the new price; the break-even repair is N × (L − a) / L [1]. Taking at least one year keeps the formula sane for a machine already past its average life: the repair then has to beat a full year of a new machine's cost.
Three things the formula leaves out, each of which you can add by hand. A new machine may use less energy, which favours replacing. A repaired machine may fail again soon, which also favours replacing. And a repair keeps a working machine out of a landfill, which some people rightly count.
Check yourself
A 2-year-old refrigerator needs a 500 repair; a new one costs 800. Fix or replace? Fix: 500 over the 11 years it has left is about 45 a year, against about 62 a year for a new one [1]. The 50% rule would have said replace.
A 12-year-old washer needs a 90 repair; a new one costs 600. Fix or replace? Replace: a washer averages 10 years, so the repair counts as buying one year at 90, against 60 a year for a new one [1].
Why can a big repair on a young machine be the better deal? Because it buys many years: the cost per year is what matters, not the size of the bill.
Example prices, not advice for a specific machine. A notebook entry for fixitornot.com, written with AI and checked by hand; the lifespans are the 2007 NAHB survey's averages, and every other figure is computed from them.