The 50/50 rule says to replace an appliance instead of repairing it when two conditions are both true: the appliance is more than 50 percent of the way through its expected lifespan, and the quoted repair costs more than 50 percent of what a comparable replacement would cost. If only one condition holds, the rule says repair. That second point is where most retellings of the rule go wrong, because people apply the cost half on its own and end up replacing a three-year-old machine over a $400 board, which is a poor decision. Used properly it is a reasonable first filter and it will give you the right answer on a typical mainstream appliance most of the time.
What it cannot do is account for parts availability, installation cost, or the enormous spread in appliance prices. It treats a $700 washer and a $9,000 built-in refrigerator as the same decision, and they are not.
Working the Rule on Real Numbers
| Appliance | Age / expected life | Repair / replacement | Rule says | We say |
|---|---|---|---|---|
| Front-load washer | 7 of 11 years (64%) | $280 / $1,100 (25%) | Repair | Repair. Agreed. |
| Front-load washer | 11 of 11 years (100%) | $850 / $1,100 (77%) | Replace | Replace. Agreed. |
| Front-load washer | 3 of 11 years (27%) | $600 / $1,100 (55%) | Repair | Repair. The rule gets this right. |
| Sub-Zero built-in refrigerator | 14 of 22 years (64%) | $1,100 / $12,000 (9%) | Repair | Repair, easily. |
| Builder-grade dishwasher | 5 of 7 years (71%) | $420 / $600 (70%) | Replace | Replace. Agreed. |
| Speed Queen washer | 12 of 20 years (60%) | $650 / $2,200 (30%) | Repair | Repair. Agreed. |
| Built-in wall oven | 16 of 18 years (89%) | $520 / $1,800 (29%) | Repair | Repair, but see the cabinetry note below. |
The rule and our own judgment agree in most of these, which is why it is worth knowing. The disagreements are instructive.
The Three Cases Where It Gives the Wrong Answer
- Built-in and integrated appliances. The rule compares the repair to the appliance price, but replacing a built-in wall oven or a panel-ready refrigerator also means cabinet modification, a custom panel, or countertop work. The true replacement cost can be double the sticker price, which pushes the ratio well below 50 percent and makes repair correct far later in life than the rule suggests.
- Discontinued parts. The rule assumes a repair is available. If the control board is no longer manufactured, a 20 percent repair ratio is irrelevant because there is no repair. Parts availability overrides the arithmetic entirely.
- Professional-grade equipment. A Wolf range, a Sub-Zero built-in, or a Speed Queen washer has both a much longer lifespan and a much higher replacement cost, so the rule almost always says repair. That is the right answer, but the rule gets there by accident rather than by understanding the appliance.
A Better Version of the Same Idea
The rule is trying to capture something true: do not sink a large fraction of replacement cost into an appliance that is nearly finished. We would phrase the test as four questions instead:
- Is the part still manufactured? If not, the decision is made.
- What is the real replacement cost, including delivery, installation, disposal, and any plumbing, gas, electrical, or cabinetry work?
- What else on this appliance is close to failing? A technician can tell you, and a second major failure within a year changes everything.
- How long will the repair realistically last? A new pump on a sound chassis buys years; a new pump in front of a failing bearing buys months.
Those four give a better answer than a ratio, and a diagnosis answers all of them. The age-banded thresholds we actually use are on is it worth paying to fix a washing machine.
Expected Lifespans to Run the Numbers
To apply any version of the rule you need the denominator. Our working figures, drawn from Boston service records:
- Washing machines: 10 to 13 years. Details on washer lifespan.
- Dryers: 12 to 15 years.
- Dishwashers: 9 to 12 years. See dishwasher lifespan.
- Refrigerators: 12 to 15 years; built-ins 15 to 25. See refrigerator repair economics.
- Ovens and ranges: 13 to 20 years. See oven lifespan.
- Microwaves: 7 to 10 years.
For a firm repair number on your own appliance, book through our appliance repair services or call for same-day dispatch.