LED Savings Calculator — Energy Cost Comparison
Calculate how much money and energy you save by switching from incandescent or CFL bulbs to LED. See annual savings, CO2 reduction, and payback period. See also our Electricity Cost Calculator and Energy Consumption Calculator.
How to Calculate LED Savings
- Count the number of bulbs you plan to replace.
- Note the wattage of your current bulbs (typically 60W or 100W incandescent).
- Find the equivalent LED wattage (usually 9W replaces 60W).
- Enter average daily usage hours and your electricity rate.
- Click Calculate to see your potential savings.
Formula
Annual kWh Saved = bulbs × (old_watts - led_watts) × hours/day × 365 / 1000
Annual $ Saved = kWh Saved × electricity rate ($/kWh)
CO2 Reduction = kWh Saved × 0.92 lbs/kWh
Payback Period = (bulbs × $3 per LED) / Annual SavingsExample
Replace 20 bulbs from 60W incandescent to 9W LED, used 5 hours/day at $0.12/kWh:
kWh Saved = 20 × (60 - 9) × 5 × 365 / 1000 = 1,861.5 kWh/year
Annual Savings = 1,861.5 × $0.12 = $223.38/year
10-Year Savings = $2,233.80
CO2 Reduction = 1,861.5 × 0.92 = 1,713 lbs/year
Payback = (20 × $3) / $223.38 = 0.3 months
LED vs Incandescent Comparison
| Incandescent (W) | LED Equivalent (W) | Lumens | Savings (%) |
|---|---|---|---|
| 40W | 6W | 450 | 85% |
| 60W | 9W | 800 | 85% |
| 75W | 11W | 1,100 | 85% |
| 100W | 14W | 1,600 | 86% |
| 150W | 20W | 2,600 | 87% |
| 200W | 28W | 3,000 | 86% |
Frequently Asked Questions
How long do LED bulbs last?
LED bulbs typically last 25,000-50,000 hours compared to 1,000 hours for incandescent bulbs. At 5 hours/day, an LED lasts about 14 years.
Are LED bulbs worth the higher upfront cost?
Yes. LED bulbs now cost $2-5 each and pay for themselves within weeks to months through energy savings. Over their lifetime, each LED saves $50-100 in electricity.
Do LEDs work with dimmer switches?
Only dimmable LEDs work with dimmer switches. Check the packaging for "dimmable" labeling. You may also need a compatible LED dimmer switch.
What color temperature should I choose?
2700K (warm white) mimics incandescent light for living spaces. 4000K (cool white) works well for kitchens and bathrooms. 5000K (daylight) suits workspaces.
Can I replace CFL bulbs with LED?
Yes. LEDs use about 25% less energy than CFLs, last 2-3 times longer, contain no mercury, and reach full brightness instantly without warm-up time.