Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Payback period
1.18
Net project cost after rebate
$15,000
Total annual savings
$12,720
Annual energy savings
84,000
Emissions avoided per year
32.42
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How to use this
- 1Enter number of fixtures.
- 2Enter existing fixture wattage (W).
- 3Enter led fixture wattage (W).
- 4Enter operating hours per year.
- 5Enter electricity rate ($/kWh).
- 6Enter installed cost per fixture ($).
- 7Enter utility rebate (total) ($).
- 8Enter annual maintenance savings ($).
- 9Read your payback period on the right — it updates as you type.
- 10Hit Share to keep the scenario or send it to someone.
About this calculator
LED retrofits are one of the highest-ROI facility upgrades available, typically paying back in one to three years through lower wattage draw, longer fixture life, and reduced HVAC load from less waste heat. This calculator compares your existing fixture wattage and count against LED replacements, computes annual energy and maintenance savings, and factors in any utility rebate to give both a simple payback period and the total cost of the project. It also estimates the emissions reduction from lower electricity draw, which most facilities now report alongside the financial payback for sustainability disclosures. The maintenance savings line often gets overlooked — LEDs typically last 25,000-50,000+ hours versus 10,000-20,000 for fluorescent and metal halide, cutting the relamping labor and material cost that facilities teams pay for year after year.
Worked example
Using the values the calculator loads with:
Inputs
- Number of fixtures: 200
- Existing fixture wattage: 150 W
- LED fixture wattage: 45 W
- Operating hours per year: 4000
- Electricity rate: 0.13 $/kWh
- Installed cost per fixture: 95 $
- Utility rebate (total): 4000 $
- Annual maintenance savings: 1800 $
Results
- Payback period: 1.18
- Net project cost after rebate: $15,000
- Total annual savings: $12,720
- Annual energy savings: 84,000
- Emissions avoided per year: 32.42
What each field means
Inputs
- Number of fixtures
- The number of fixtures used in the calculation. Starts at 200 so you have a working example on load.
- Existing fixture wattage (W)
- The existing fixture wattage used in the calculation, measured in W. Starts at 150 W so you have a working example on load.
- LED fixture wattage (W)
- The led fixture wattage used in the calculation, measured in W. Starts at 45 W so you have a working example on load.
- Operating hours per year
- The operating hours per year used in the calculation. Starts at 4000 so you have a working example on load.
- Electricity rate ($/kWh)
- The electricity rate used in the calculation, measured in $/kWh. Starts at 0.13 $/kWh so you have a working example on load.
- Installed cost per fixture ($)
- The installed cost per fixture used in the calculation, measured in $. Starts at 95 $ so you have a working example on load.
- Utility rebate (total) ($)
- The utility rebate (total) used in the calculation, measured in $. Starts at 4000 $ so you have a working example on load.
- Annual maintenance savings ($)
- The annual maintenance savings used in the calculation, measured in $. Starts at 1800 $ so you have a working example on load.
Results
- Payback period
- Returned as a decimal number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Net project cost after rebate
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Total annual savings
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Annual energy savings
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Emissions avoided per year
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Does this account for HVAC savings from reduced heat output?
Not directly — LEDs produce far less waste heat than the fixtures they replace, which can trim cooling load in conditioned spaces by a small but real amount. Add that as extra annual savings if you have a rough estimate; most facilities see it as a 3-8% bonus on top of the lighting energy savings shown here.
How do I find utility rebates for my project?
DSIRE (dsireusa.org) maintains a database of utility and state incentive programs searchable by ZIP code. Most investor-owned utilities offer prescriptive per-fixture rebates for LED retrofits that don't require pre-approval below a certain project size, which is the fastest path to capturing the incentive.
What payback period is considered a good project?
Most facilities capital committees approve lighting retrofits with paybacks under 3 years without much debate; 1-2 years is common for fluorescent-to-LED conversions with rebates applied. Beyond 4-5 years, competing capital priorities usually win out unless there's a compliance or tenant-satisfaction driver pushing the project.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
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Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). LED Retrofit Payback Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/led-retrofit-payback
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/led-retrofit-payback" target="_blank" rel="noopener">LED Retrofit Payback Calculator — RevenueLab</a> (2026).</p>
Source: [LED Retrofit Payback Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/led-retrofit-payback) (2026).