The 50% Rule (and Why It's Not Enough)
The most common rule of thumb is: "If the repair costs more than 50% of the replacement price, replace it." This is a reasonable starting point, but it ignores critical factors like the appliance's remaining lifespan, energy efficiency, and future failure risk.
A $350 repair on a 3-year-old washing machine with 10 years of life ahead is very different from a $350 repair on a 12-year-old machine that could break again next year.
The Multi-Factor Framework
A proper repair vs. replace analysis weighs multiple factors, each contributing to the overall decision:
Repair-to-Cost Ratio
30%How expensive is the repair relative to buying new? Below 30% strongly favors repair; above 50% strongly favors replacement.
Remaining Lifespan
25%What percentage of the appliance's expected life remains? More than 50% remaining favors repair; less than 25% favors replace.
Failure Risk (3-year)
20%What's the probability the appliance will fail again within 3 years? Modeled using an aging failure curve.
Break-Even Timeline
15%How many years until a new, more efficient appliance 'pays for itself' through lower operating costs?
Energy Efficiency Delta
10%How much more efficient is a new model? If the new one uses 30%+ less energy, replacement is more attractive.
The Failure Probability Curve
One of the most important — and least intuitive — factors in repair vs. replace is the cumulative failure probability. Appliances don't fail randomly; their failure rate increases with age. A typical model adds roughly 2% to the annual failure probability for each year of age, starting from a baseline of about 3%.
Annual failure probability by appliance age (simplified model)
The cumulative 3-year failure probability is calculated by combining each year's individual rate. For an 8-year-old appliance, the probability of at least one failure over the next 3 years can exceed 50% — meaning there's a coin-flip chance you'll need another repair soon.
Energy Efficiency: The Slow Burn
An old appliance might work fine but consume significantly more energy than a modern equivalent. A 15-year-old refrigerator can use 40-50% more electricity than a current Energy Star model. At today's electricity prices — with annual inflation of 3-5% — that efficiency gap compounds year after year.
The break-even calculation tracks when the cumulative energy savings of a new appliance offset its higher purchase price. If the break-even is 3 years but the new appliance lasts 12, you get 9 years of "free" savings.
Run the Analysis
Our Repair vs. Replace calculator uses all five factors — cost ratio, remaining lifespan, failure risk, break-even analysis, and energy efficiency — weighted together into a single verdict with confidence score.
Try Repair vs. Replace