A homeowner called me last spring about a 12-year-old dishwasher that wouldn't drain. The repair quote was $340. A solid new mid-range unit, installed, runs about $850. She wanted to fix it, save the cash, and move on. I get it. But I asked her one question: how old is it, and how much does the fix cost? That little math problem decides most of these jobs.
I have priced thousands of repairs over the years, and the same trap shows up again and again. People pour $300 into a machine, then $250 more six months later, and a year in they have spent the price of a new one anyway, just slower and with more headaches. The smart move is rarely about the single repair in front of you. It is about whether you are about to start feeding a money pit.
There is a clean rule for this, and the numbers behind it are simple. Let me walk you through it.
The 50 Percent Rule, plain and simple
Here is the rule I give everyone: if a repair costs more than 50 percent of a new appliance, and the unit is past half its expected lifespan, replace it. If the repair is cheap or the machine is young, fix it.
That is the whole thing. It works because it bundles two questions into one decision: are you throwing good money after a machine that is on its way out, and is the fix worth what a fresh unit would cost?
Run the dishwasher example. A $340 repair on a unit that replaces for $850 is 40 percent of new. Under 50 percent, so far so good. But the machine is 12 years old, and dishwashers typically last 9 to 12 years. It is past its lifespan. When the rule is mixed (one signal says fix, the other says replace), I lean on age. An old machine will find a new way to break.
Repair cost divided by new-unit cost (installed). Over 50 percent? Replace. Under 50 percent but the appliance is past half its rated life? Still lean toward replace. Under 50 percent and the machine is young? Fix it without much worry.
What appliances actually cost to replace
You cannot run the rule without knowing the replacement number, and "new" means installed, not just the sticker price. Haul-away and hookup are real money. Here are honest ranges I see in 2026, mid-grade gear, install included.
- Dishwasher: roughly $650 to $1,100 installed.
- Refrigerator: typically around $1,000 to $2,500.
- Clothes washer: roughly $700 to $1,300.
- Electric or gas range: around $800 to $2,000.
- Water heater (tank): roughly $1,400 to $2,800 installed.
- Microwave (over-range): around $350 to $600.
On the repair side, most service calls break into a diagnostic fee (often $75 to $150, sometimes credited toward the work), labor, and the part. A control board can run $200 to $500 in parts alone. A water inlet valve or a heating element is often $150 to $300 all in. That spread is exactly why the 50 percent line matters.
Lifespan: how long these things are really supposed to last
Half the decision is age, so know the clock you are working against. Rough rated lifespans: refrigerators 12 to 15 years, dishwashers 9 to 12, clothes washers 10 to 13, gas ranges 15 to 17, electric ranges 13 to 15, tank water heaters 8 to 12.
If your appliance is comfortably under half that range, almost any reasonable repair is worth it. Once you cross into the back half, every repair gets a harder look, because you are not just paying for this fix, you are betting on what comes next.
Repair vs replace, side by side
Here is how the two paths stack up. I am framing a typical case: an aging appliance somewhere past the halfway mark on its life, the kind of unit where people actually agonize over this.
| Factor | Repair the old unit | Replace with new |
|---|---|---|
| Upfront cost | Low to moderate ($150-$500 typical) | High ($650-$2,500+ installed) |
| Expected added lifespan | Short, often 1-4 years on an old machine | Long, full 10-15 year run |
| Ongoing upkeep | Rising, more breakdowns likely ahead | Low, often under warranty for years |
| Energy and water cost | Higher on older, less efficient units | Lower, newer models cut utility bills |
| Risk | Repeat failures, leaks, possible water damage | Mostly install errors, covered by warranty |
| Best when | Young machine, cheap fix, under 50 percent | Old machine, costly fix, over 50 percent |
The risk row is the one homeowners underweight. A failing washer or water heater does not just stop working, it can leak. I have seen a $200 repair decision turn into a flooded laundry room, and suddenly you are pricing out what water damage repair actually costs, which dwarfs any appliance. That downside belongs in your math.
The hidden costs that quietly tip the decision
The sticker prices above are only part of the picture. A few things move the number in ways people forget until the bill lands.
Repeat repairs. One fix on an old machine is rarely the last. When the heating element goes, the pump and the control board are often not far behind. Add a second likely repair to your repair-side total before you compare.
Energy and water. A 14-year-old fridge or a worn water heater can cost noticeably more to run each year than a current model. Over the few years you would squeeze out of a repair, that gap eats part of your "savings."
Install surprises. Old shutoff valves that crumble when touched, a worn supply line, an electrical or venting setup that is no longer up to code. These add $50 to a few hundred on a replacement. Not deal-breakers, but budget for them.
Get the diagnostic done before you decide, even if it costs $100. A good tech tells you not just what failed but what is likely next. "Replace this valve and you are fine for years" is a very different answer than "this board is going, and the compressor is tired too." That second answer is your replace signal.
The verdict: who should fix, who should replace
Fix it if the appliance is under half its rated life and the repair lands well below 50 percent of a new unit. A 4-year-old washer with a $180 pump replacement? Repair it every time. Same with simple, known fixes like a fridge door gasket or a dryer belt.
Replace it if the machine is past the halfway mark and the repair crosses 50 percent, or if this is the second real repair in a year. Also replace, almost regardless of price, anything that poses a safety or water risk you cannot trust, like a leaking water heater near finished space.
And do not let a working machine become a problem you ignore. Appliances on their way out usually warn you first, the same way other home systems do. Knowing which repairs you should never put off keeps a cheap fix from becoming an expensive emergency. The principle is the same one I preach on heating and cooling: matching the equipment to the job and the timing matters more than the brand. If you are replacing an HVAC unit, the same logic and the right-sizing guidance in our HVAC sizing guide applies double, since an oversized swap wastes money for a decade.
Does the 50 percent rule work for every appliance?
It works as a starting point for all major appliances, but weight age heavily on units with expensive core parts, like refrigerator compressors or washer transmissions. When a core component fails on an old machine, replace even if the quote is under 50 percent.
Should I count the diagnostic fee in the repair cost?
Yes, count it. Many shops credit the $75 to $150 diagnostic toward the repair if you proceed, so ask. If it is not credited, add it to your repair total before comparing against the price of a new unit.
Are extended warranties worth it on a new appliance?
Usually not on basic units, since the factory warranty covers the early failure window. They can make sense on high-end refrigerators or front-load washers where a single board or compressor repair runs $400 or more. Read what is actually covered before buying.
So before you hand over $340 to keep an old machine limping along, do the two-line math: what does the fix cost against a new one, and where is this thing in its life. That dishwasher owner? She replaced it. Six months later she thanked me, because the old one's pump went next, and she would have been right back where she started. A little math up front saves you the slow bleed.
