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Exterior Lighting Retrofit Payback Calculator

LED exterior retrofit cuts energy 50-70% and maintenance; fast payback on parking lots.

Fixture count

Current watts

LED watts

Hours / day

$/kWh

Retrofit $/fixture

Rebate $/fixture

Payback months

16.8

Annual savings

$5,361

Net investment

$7,500

How the math works

Savings = fixtures × watts saved × hrs × 365 / 1000 × rate. Net = fixtures × (cost − rebate).

60 × 170 × 12 × 365 / 1000 × $0.12 = $5,366/yr. Net $7,500. Payback 16.8 mo.

Editorial noteMaintained by EveryCalc - Reviewed June 2026

EveryCalc calculators are designed for fast, practical estimates with transparent inputs and no required account. We use plain formulas, visible assumptions, and related tools so visitors can check the result from more than one angle.

Results are informational only. For financial, tax, legal, medical, construction, or other high-impact decisions, verify the output against primary sources or a qualified professional.

Learn more about our review process on the EveryCalc methodology page.

How this calculator works

What this page estimates

This Exterior Lighting Retrofit Payback Calculator is built to give a quick, browser-based estimate for exterior lighting retrofit payback. LED exterior retrofit cuts energy 50-70% and maintenance; fast payback on parking lots. The inputs stay on the page during normal use, and the result should be treated as an estimate for planning, comparison, or education rather than professional advice.

Calculation approach

The calculator applies the standard relationship implied by the inputs, then formats the answer so it can be checked and reused. For finance tools, the most important step is using consistent units, rates, time periods, and assumptions before comparing the result with another calculator or outside quote.

Example workflow

For example, start with a realistic value you already know, change one input at a time, and watch how the answer moves. That makes it easier to tell whether the result is being driven by the main amount, the rate, the time period, or a unit conversion.

Practical checks

Use current, real-world numbers when the result affects money, health, tax, or legal decisions.
Run a low, base, and high case when the inputs are estimates.
Check the related calculators below when the next decision depends on a different assumption.

How to interpret the exterior lighting retrofit payback result

Best use

Use the result as a planning number for comparing payments, rates, returns, tax reserves, or cash-flow choices before you request a quote or make a commitment.

Cross-check

Compare the answer with the contract, lender estimate, tax form, brokerage statement, payroll record, or invoice that will control the real-world outcome.

Watch for

Do not rely on a single optimistic rate, return, or fee assumption. Money pages work best when you run low, base, and high cases and keep professional advice separate from the estimate.

This page belongs to the Finance calculator library, so the answer should be read in the context of the decision you are modeling rather than as a universal rule.

Before relying on this exterior lighting retrofit payback estimate

Most calculator mistakes come from the inputs, not the arithmetic. Use this short audit before you reuse the answer in a spreadsheet, quote, application, or important conversation.

Confirm source numbers

Match balances, rates, fees, taxes, income, and payment dates against the lender quote, payroll record, tax form, statement, invoice, or contract.

Separate cash flow from total cost

A lower monthly payment can still cost more over time if fees, interest, taxes, or a longer term are hidden in the structure.

Run conservative cases

Test at least one higher-cost or lower-return case before using the output for a purchase, refinance, investment, loan, or tax decision.

Rerun this page when the rate, price, term, fee, tax rule, income, expense, or expected holding period changes.

How to Use

Enter fixture count.
Enter current fixture wattage.
Enter LED replacement wattage.
Enter hours per day burn.
Enter electricity rate.
Enter retrofit cost per fixture.
Read payback.

Frequently Asked Questions

Exterior LED options?

LED retrofit kit (keeps fixture, replaces lamp/ballast): $75-250/fixture. Full LED fixture replacement: $200-800/fixture. Wallpacks: $150-400. Pole lights: $300-900. Wet-location ceiling mount: $200-500. Photocell + motion sensor add-on: $50-150 per fixture. Commercial contractor install: $100-300 labor per fixture. Night-only burn hours: 10-14 per day.

Energy savings?

Metal halide 175W fixture → LED 60W: 66% reduction. HPS 250W → LED 80W: 68% reduction. Annual savings: 250W × 12 hrs × 365 × $0.12 / 1000 = $131/fixture/year baseline. LED: $42/fixture/year. Savings: $89/fixture/year. 50 fixtures: $4,450/year. Payback 1-3 years typical on $75-300 cost per fixture.

Maintenance savings?

Metal halide/HPS bulb replacement: every 2-4 years, $30-120 per bulb + $50-200 labor = $80-320/fixture every 3 yr = $27-107/fixture/year. LED: 10-15 year life, very few replacements. Savings: $25-100/fixture/year on maintenance. Ladder/bucket truck rental: $300-800/day for maintenance rounds. Reduced frequency = major operational savings.

Utility rebates?

Most utilities offer prescriptive LED rebates: $50-300 per exterior fixture. DesignLights Consortium (DLC) qualified fixtures required. Prescriptive rebate: simple, per-fixture payment. Custom rebate: based on calculated energy savings, $0.05-0.15/kWh reduction. Stack with federal 179D deduction (commercial): $0.30-2.00/sqft deduction. Total rebates can cover 30-60% of fixture cost.