Calculating your yearly saving per bulb is straightforward once you know the LED Bulb Savings formula and what each input means. This guide explains the method in plain language, walks through a manual calculation, and gives worked examples you can follow — then you can do it instantly with the LED Bulb Savings Calculator.
What is LED Bulb Savings?
The LED Bulb Savings calculation tells you your yearly saving per bulb from a few simple inputs. The figure you are solving for here is the yearly saving per bulb, expressed in INR.
The LED Bulb Savings formula
The core formula is:
Yearly saving per bulb = (Old bulb wattage - LED wattage) × Hours used per day × Days per year ÷ 1000 × Electricity rateHere is what each input means:
- Old bulb wattage — a value measured in W. Example: 60 W.
- LED wattage — a value measured in W. Example: 10 W.
- Hours used per day — a number. Example: 5.
- Days per year — a number. Example: 365.
- Electricity rate — a money amount. Example: ₹8.
How to calculate it step by step
- Write down the old bulb wattage (for example, 60 W).
- Write down the led wattage (for example, 10 W).
- Write down the hours used per day (for example, 5).
- Write down the days per year (for example, 365).
- Write down the electricity rate (for example, ₹8).
- Apply the formula above to get your yearly saving per bulb.
- Double-check the result with the LED Bulb Savings Calculator.
Worked examples
Example 1
| Input / Output | Value |
|---|---|
| Old bulb wattage | 60 W |
| LED wattage | 10 W |
| Hours used per day | 5 |
| Days per year | 365 |
| Electricity rate | ₹8 |
| Yearly saving per bulb | ₹730.00 |
With old bulb wattage of 60 W, led wattage of 10 W, hours used per day of 5 and days per year of 365, the yearly saving per bulb works out to ₹730.00.
Example 2
With old bulb wattage of 120 W, led wattage of 10 W, hours used per day of 5 and days per year of 365, the yearly saving per bulb works out to ₹1,606.00.
| Result | Value |
|---|---|
| Yearly saving per bulb | ₹1,606.00 |
Example 3
With old bulb wattage of 30 W, led wattage of 10 W, hours used per day of 5 and days per year of 365, the yearly saving per bulb works out to ₹292.00.
| Result | Value |
|---|---|
| Yearly saving per bulb | ₹292.00 |
Tips for an accurate result
- Keep your units consistent — mixing, say, months with years or grams with kilograms is the most common source of error.
- Round only at the very end. Rounding inputs early can shift the final answer noticeably.
- Re-run the numbers whenever an input changes, rather than estimating from an old result.
Prefer not to do the maths by hand? — the LED Bulb Savings Calculator does it instantly, for free, with the formula and a worked example built in.
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