Aisha K.
Mar 12, 2026
Clean layout and the results update instantly. Exactly what I needed for a quick planning check.
Electrical & Wiring
LED Retrofit Payback Calculator
Savings = (old W − LED W) × hours × rate; payback = retrofit cost ÷ annual savings.
Calculate LED retrofit savings and payback period. Planning estimates only — verify measurements and local codes on site.
Inputs
5200
350
124
5200
0.050.5
1500
Smart analysis
Recommendations
Tailored to your live inputs and result—guidance only, not professional advice.
- Interpret
Treat this as a planning estimate
Primary result: Annual savings = $282.07. Re-run with optimistic and pessimistic inputs to understand the range—not just a single point.
Scenario studio
Compare A vs B
Capture two sets of inputs on this device, then see which outcome wins. Share either scenario with a link.
Scenario A
Adjust inputs, then capture this slot.
Scenario B
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Plain-English guide
Terms & how it works
Confused by a field? Read the short definitions here while you use the tool.
Old fixture watts
The “Old fixture watts” value used in this tool’s formula. Adjust it to see results update live.
LED watts
The “LED watts” value used in this tool’s formula. Adjust it to see results update live.
Hours per day
The “Hours per day” value used in this tool’s formula. Adjust it to see results update live.
Retrofit cost per fixture
One-time or recurring costs that affect total money paid.
Electric rate ($/kWh)
The “Electric rate ($/kWh)” value used in this tool’s formula. Adjust it to see results update live.
Fixture count
The “Fixture count” value used in this tool’s formula. Adjust it to see results update live.
- retrofitCost
Retrofit cost per fixture ($)
The “Retrofit cost per fixture ($)” field. Default 25; typical range 5–200.
How this calculator works
Calculate LED retrofit savings and payback period. Planning estimates only — verify measurements and local codes on site. Savings = (old W − LED W) × hours × rate; payback = retrofit cost ÷ annual savings. Example: 32 W → 9 W × 12 hrs/day × 365 at $0.14/kWh saves ~$20/yr per bulb.
Savings = (old W − LED W) × hours × rate; payback = retrofit cost ÷ annual savings.
Example: 32 W → 9 W × 12 hrs/day × 365 at $0.14/kWh saves ~$20/yr per bulb.
When to use this LED Retrofit Payback
Common use cases
- Calculate LED retrofit savings and payback period.
- Sanity-check with this case: 32 W → 9 W × 12 hrs/day × 365 at $0.14/kWh saves ~$20/yr per bulb.
- The relationship is: Savings = (old W − LED W) × hours × rate; payback = retrofit cost ÷ annual savings.
Localized examples
- Electrical & Wiring: the example on this page uses the same formula as the widget.
What you get
- Fields: Old fixture watts, LED watts, Hours per day, Retrofit cost per fixture ($)
- Savings = (old W − LED W) × hours × rate; payback = retrofit cost ÷ annual savings.
- Example on the page: 32 W → 9 W × 12 hrs/day × 365 at $0.14/kWh saves ~$20/yr per bulb.
How to Calculate LED Retrofit Payback Step-by-Step
- 1Enter Old fixture watts, LED watts, Hours per day, then the remaining fields. Use the values you have, not a catalog average, unless that is all you know.
- 2Savings = (old W − LED W) × hours × rate; payback = retrofit cost ÷ annual savings.
- 3Worked case: 32 W → 9 W × 12 hrs/day × 365 at $0.14/kWh saves ~$20/yr per bulb.
- 4Buy materials after you walk the job. This is a first-pass quantity, not a purchase order.
Governing formula
Savings = (old W − LED W) × hours × rate; payback = retrofit cost ÷ annual savings.
32 W → 9 W × 12 hrs/day × 365 at $0.14/kWh saves ~$20/yr per bulb.
Example: set Old fixture watts = 32, LED watts = 9, Hours per day = 12, then read the result.
Variable definitions
- oldWatts
Old fixture watts
The “Old fixture watts” field. Default 32; typical range 5–200.
- ledWatts
LED watts
The “LED watts” field. Default 9; typical range 3–50.
- hoursPerDay
Hours per day
The “Hours per day” field. Default 12; typical range 1–24.
- retrofitCost
Retrofit cost per fixture ($)
The “Retrofit cost per fixture ($)” field. Default 25; typical range 5–200.
- kwhRate
Electric rate ($/kWh)
The “Electric rate ($/kWh)” field. Default 0.14; typical range 0.05–0.5.
- fixtureCount
Fixture count
The “Fixture count” field. Default 20; typical range 1–500.
- The takeoff (Savings = (old W − LED W) × hours × rate; payback = retrofit cost ÷ annual savings.) ignores waste, code, and what you find when you open the wall. Measure twice on site.
- Nothing here is uploaded for the calculation itself.
Frequently Asked Questions
Savings = (old W − LED W) × hours × rate; payback = retrofit cost ÷ annual savings.
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Community
Reviews & Ratings
See what others think about this tool, then leave your own rating to help improve CalculioHub.
4.8
out of 5.0
4 reviews
Daniel R.
Feb 28, 2026
Very usable on mobile. Would love a save/export option later, but the math feels solid.
Priya S.
Feb 3, 2026
The FAQ section answered my questions before I even had to search. Smooth dark mode too.
Marcus L.
Jan 19, 2026
Simple inputs, clear outputs. This replaced three bookmarks I used to juggle.
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