# My energy cost calculator

We use cost calculation all the times for variety of items including student loan, mortgage, gas mileage and medical bills. We do side by side comparaison over and over before making the final decision. This process is time consuming.

What if we create a simple calculator that would do the hard work and gives us an instant feedback.

This calculator calculates the annual cost of energy usage by four light bulbs (Incandescent, Halogen, Compact Fluorescent Lamps (CFL) and Light-Emitting Diode (LED)) and makes the comparison easier.

#### Incandescent

{{inc_wattage}}

{{inc_cost}}

#### Halogen

{{hal_wattage}}

{{hal_cost}}

#### CFL

{{cfl_wattage}}

{{cfl_cost}}

#### LED

{{led_wattage}}

{{led_cost}}

This calculator is using a very simple equation and connot be used for more accurate energy usage.

We take into account three component of the energy cost the lumens, Kilowatt-hour cost and hours of usage.

**Lumen** is the unit of luminous flux. It measures the total quantity of visible light emitted by the light bulb per unit of time.

We convert the lumen to Watt by applying a conversion rate.

**Kilowatt-hour** is a unit of energy. When the power is transmitted over a period of time, the total energy is the power (in kilowatts) multiplied by the time (in hours).

The Kilowatt-hour is mostly used as billing unit by the energy company for billing purpose.
**Hours of usage** is the length of time (in hours) the energy was delivered to the light bulb.

This calculator is using the power of AngularJS for all calculation.