Repair vs Replace Microwave: Break-Even Calculator 2026

The repair wins today — the replacement wins the decade

A microwave repair is cheap and a new microwave is not — but a new microwave runs cheaper every year, and over a decade that saving adds up. The repair total is just the repair cost: $120.00. The replace total is the new price, minus the saving over the old machine’s remaining life, plus disposal: $350 − $25 × 5 + $20 = $245.00. On the defaults — repair $120.00, new microwave $350.00, remaining life 5 years, saving $25.00/year, disposal $20.00 — REPAIR wins by $125.00; cost per year repair $24.00 vs replace $49.00; break-even repair $245.00, break-even price $225.00, break-even life 10.00 yrs (exact 10.0000), break-even saving $50.00/yr, break-even disposal none (-$105.00); 10-year repair-then-replace $365.00 vs replace-now $120.00 — REPLACE wins by $245.00 over 10 years.

At the defaults — repair $120.00, new microwave $350.00, remaining life 5 years, saving $25.00/year, disposal $20.00 — the repair total is $120.00, the replace total is $245.00, REPAIR wins by $125.00; cost per year repair $24.00 vs replace $49.00; break-even repair $245.00, break-even price $225.00, break-even life 10.00 yrs (exact 10.0000), break-even saving $50.00/yr, break-even disposal none (-$105.00); 10-year repair-then-replace $365.00 vs replace-now $120.00 — REPLACE wins by $245.00 over 10 years. Check the identities: repair = R; replace = P − S × L + D; difference = replace − repair; break-even repair cost = replace total; break-even new price = R + S × L − D; break-even remaining life = (P + D − R) ÷ S; break-even annual saving = (P + D − R) ÷ L; break-even disposal = R − P + S × L; 10-year repair-then-replace = R + P + D − S × (10 − L); 10-year replace-now = P + D − S × 10. Rounding convention: totals are computed from unrounded values, so rounded parts may differ by a cent from their rounded sum.

The worked example, line by line

Setup: repair $120.00, new microwave $350.00, remaining life 5 years, saving $25.00/year, disposal $20.00.

Line 1 — the repair total. The repair total is the repair cost: $120.00.

Line 2 — the replace total. $350 − $25 × 5 + $20 = $350 − $125 + $20 = $245.00. The five years of saving shave $125 off the new microwave’s price.

Line 3 — the winner. $245.00 − $120.00 = $125.00, so REPAIR wins by $125.00. Cost per year: $120 ÷ 5 = $24.00 for the repair, $245 ÷ 5 = $49.00 for the replacement.

Line 4 — the break-evens. The break-even repair cost is the replace total, $245.00. The break-even new price is $120 + $25 × 5 − $20 = $225.00. The break-even remaining life is ($350 + $20 − $120) ÷ $25 = 10.00 yrs (exact 10.0000). The break-even annual saving is ($350 + $20 − $120) ÷ 5 = $50.00/yr. The break-even disposal is $120 − $350 + $25 × 5 = -$105.00 — none, because the disposal cost that would tie is negative.

Line 5 — the 10-year lens. Repair now, then replace in 5 years: $120 + $350 + $20 − $25 × 5 = $365.00. Replace now: $350 + $20 − $25 × 10 = $120.00. So REPLACE wins by $245.00 over 10 years — the verdict flips over 10 years.

Reverse: the break-even repair cost is $245.00 (exact $245.00); a $245.00 repair costs $245.00, exactly tying the replace total — verdict: TIE. The break-even new price is $225.00 (exact $225.00); a $225.00 microwave costs $120.00 to replace, tying the repair — verdict: TIE. The break-even remaining life is 10.00 yrs (exact 10.0000); at 10.00 yrs the replace total is $120.00 (TIE), at 9.99 yrs it is $120.25 (REPAIR wins by $0.25), at 10.01 yrs it is $119.75 (REPLACE wins by $0.25) — 10.00 is the exact tie. The break-even annual saving is $50.00/yr (exact $50.00); at $50.00/yr saving the replace total is $120.00, tying the repair — verdict: TIE. The break-even disposal is none — the disposal cost that would tie is -$105.00; repairing wins even with free disposal — verdict: NONE. The 10-year lens: repair-then-replace $365.00 vs replace-now $120.00 — REPLACE wins by $245.00 over 10 years.

Every branch, checked

Repair $300: Repair $300.00, replace $245.00 — REPLACE wins by $55.00. 10-year: $545.00 vs $120.00 — REPLACE wins by $425.00 over 10 years. A $300 repair costs more than the $245.00 replacement — REPLACE wins by $55.00, a flip from the default verdict.

Repair $400: Repair $400.00, replace $245.00 — REPLACE wins by $155.00. 10-year: $645.00 vs $120.00 — REPLACE wins by $525.00 over 10 years. At $400 the repair is nearly twice the replacement cost — REPLACE wins by $155.00.

12 years left: Repair $120.00, replace $70.00 — REPLACE wins by $50.00. 10-year: $540.00 vs $120.00 — REPLACE wins by $420.00 over 10 years. Twelve years of $25 savings are worth $300, so the replace total falls to $70.00 and REPLACE wins by $50.00.

13 years left: Repair $120.00, replace $45.00 — REPLACE wins by $75.00. 10-year: $565.00 vs $120.00 — REPLACE wins by $445.00 over 10 years. One more year of saving drops the replace total to $45.00 — REPLACE wins by $75.00.

Saving $60/year: Repair $120.00, replace $70.00 — REPLACE wins by $50.00. 10-year: $190.00 vs -$230.00 — REPLACE wins by $420.00 over 10 years. A $60-a-year saving pays for the new microwave fast — the replace total is $70.00 and REPLACE wins by $50.00; over 10 years the replace-now total is -$230.00.

Saving $0/year: Repair $120.00, replace $370.00 — REPAIR wins by $250.00. 10-year: $490.00 vs $370.00 — REPLACE wins by $120.00 over 10 years. With no saving the new microwave costs its full price plus disposal — $370.00 — so REPAIR wins by $250.00 and the break-even remaining life is — (no saving, so no life ever ties).

New microwave $250: Repair $120.00, replace $145.00 — REPAIR wins by $25.00. 10-year: $265.00 vs $20.00 — REPLACE wins by $245.00 over 10 years. A cheaper new microwave narrows the gap to $145.00 — but REPAIR wins by $25.00, the closest call on the page.

New microwave $600: Repair $120.00, replace $495.00 — REPAIR wins by $375.00. 10-year: $615.00 vs $370.00 — REPLACE wins by $245.00 over 10 years. A $600 microwave is four times the repair — REPAIR wins by $375.00.

Disposal $0: Repair $120.00, replace $225.00 — REPAIR wins by $105.00. 10-year: $345.00 vs $100.00 — REPLACE wins by $245.00 over 10 years. Free haul-away drops the replace total to $225.00 — REPAIR wins by $105.00.

Disposal $100: Repair $120.00, replace $325.00 — REPAIR wins by $205.00. 10-year: $445.00 vs $200.00 — REPLACE wins by $245.00 over 10 years. A $100 disposal fee pushes the replace total to $325.00 — REPAIR wins by $205.00.

What the defaults assume

The model assumes the repair restores the old microwave for its full remaining life, and that the new microwave’s saving is the same every year — it does not model a repair that fails again, a new microwave that breaks early, or energy prices changing. It assumes the disposal fee is paid when you replace, not when you repair — you keep the old machine either way. It assumes the saving is real money: $25 a year of lower energy and fewer service calls. With a $0 repair the total is $0.00 and REPAIR wins by $245.00. With 1 year left and no saving the break-even life is — — at the model level there is no life that ties, because the saving is $0; at the calc level S = 0 is valid input and the break-even-life field renders —. Rounding convention: totals are computed from unrounded values, so rounded parts may differ by a cent from their rounded sum; the reverses are nearest-value solutions, and the exact unrounded figures ($245.00, $225.00, 10.0000, $50.00, -$105.00) are stated wherever the rounded figures appear.

Output · formula · meaning

Who uses this

• The homeowner with a $120 repair quote: they learn REPAIR wins by $125.00 — and they check the $300 branch (REPLACE wins by $55.00) to see the repair price where replacing wins.
• The renter whose microwave has 12 years left: they learn REPLACE wins by $50.00 — twelve years of saving beat the repair outright — and they check the 13-year branch (REPLACE wins by $75.00) to see the margin grow.
• The shopper eyeing a $250 microwave: they learn REPAIR wins by $25.00 — the closest call on the page — and they check the $600 branch (REPAIR wins by $375.00) to see how fast a dearer model loses.
• The planner thinking in decades: they learn the 10-year lens flips the verdict — REPLACE wins by $245.00 over 10 years — and they check the $60-a-year branch (REPLACE wins by $420.00 over 10 years) to see the decade margin widen.

Accuracy & limitations

The math is first-principles comparison: repair = R; replace = P − S × L + D; difference = replace − repair; cost per year = total ÷ L; break-even repair cost = replace total; break-even new price = R + S × L − D; break-even remaining life = (P + D − R) ÷ S; break-even annual saving = (P + D − R) ÷ L; break-even disposal = R − P + S × L; 10-year repair-then-replace = R + P + D − S × (10 − L); 10-year replace-now = P + D − S × 10. The 4-decimal exact is shown where the rounding matters: the break-even remaining life is 10.0000 (shown as 10.00 yrs); at 10.00 yrs the replace total is $120.00 (TIE), at 9.99 yrs it is $120.25 (REPAIR wins by $0.25), at 10.01 yrs it is $119.75 (REPLACE wins by $0.25). What the model cannot do is predict a microwave’s real life: a repair can fail again, a new microwave can break early, and the saving depends on how much you use it — the break-even life of 10.00 yrs is the number to compare against your honest estimate of the old machine’s remaining life. For the same question on a bigger appliance, see the repair vs replace washing machine calculator; for the dryer, see the repair vs replace dryer calculator; for the dishwasher, see the repair vs replace dishwasher calculator. This is a calculator, not a repair manual.