Electricity calculator
LED Savings Calculator
Estimate monthly and yearly savings from replacing older bulbs with LED bulbs.
When to use this calculator
Use this calculator when replacing incandescent, halogen, or older bulbs with LEDs. It helps estimate whether the upgrade is worth doing across one room, an apartment, or a whole home.
LED savings are strongest where many bulbs run for long hours. Hallways, outdoor lights, kitchens, and work areas often show better savings than rarely used closets.
Formula used
Savings = (old watts − LED watts) ÷ 1,000 × bulbs × hours per day × 30 × electricity rate.
The formula is intentionally simple so it can be used for quick planning. Real bills, quotes, and installation costs can include fixed fees, taxes, tiers, labor, product limits, and site-specific conditions that a calculator cannot see.
Input guide
| Input | How to use it |
|---|---|
| Old bulb watts | The wattage of the existing bulb type. |
| LED watts | The replacement bulb wattage with similar brightness. |
| Number of bulbs | Count only bulbs you plan to replace. |
| Hours per day | Use realistic average use for that group of lights. |
Examples
Eight-bulb room
Replacing eight 60 W bulbs with 9 W LEDs used 5 hours daily saves about 61.2 kWh per month.
Yearly view
Small monthly savings become more meaningful when multiplied by 12 months and many bulbs.
How to get a more accurate result
- Group bulbs by usage pattern instead of averaging the whole home blindly.
- Compare lumens, not only watts, so brightness stays similar.
- Include bulb purchase cost when calculating payback.
Common mistakes to avoid
- Replacing rarely used bulbs first and expecting big savings.
- Choosing LEDs with the wrong color temperature or brightness.
- Ignoring dimmer compatibility.
Quick checklist before relying on the result
- Count bulbs.
- Record old watts.
- Choose equivalent LED lumens.
- Estimate daily hours.
FAQ
Are LEDs always worth it?
Usually for frequently used lights, but payback is slower for rarely used bulbs.
Should I compare watts or lumens?
Use watts for cost and lumens for brightness.
Why do some LEDs flicker?
Some fixtures or dimmers are not compatible with the bulb driver.