Units help us define what we are talking about. For instance, if I just said that the outlet had a lot of voltage, it doesn't mean much. However, if I say that the outlet has 120 V, then most people understand what that means. This understanding comes from the units. However, units can be difficult.
The following video will teach you about units and about how to discuss these units.
What is milliamp? What is Megaohms? We will discuss what these mean and how to address the most common units that you will see in basic electrical. Select a prefix from the drop down below to see each value.
Prefix (symbol) | Value |
---|---|
milli (m) | 1/1000 |
micro (µ) | 1/1000,000 |
nano (n) | 1/1000,000,000 |
Pico (p) | 1/1000,000,000,000 |
kilo (k) | 1000 |
Mega (M) | 1000,000 |
Giga (G) | 1000,000,000 |
Tera (T) | 1000,000,000,000 |
Using the prefixes, I can change my units so that it makes more sense. The following is an example for common units that we will use.
Let's say that I have 1000 volts. This would be displayed as 1000 V. We know from the table above that kilo means 1000. So, 1000 V = 1 kV or 1 kilovolt. Calculate your value. Then mouse over the black box to see if you are correct.
Formulas | ||
kV * 1000 = V V / 1000 = kV |
Examples | ||
2500 V = 2.5 kV 17 kV = 17000V 120 V = 0.120 kV 480 V = 0.480 kV |
From the chart, we see that a millivolt is 1/1000 of a volt. This means that for every volt, I have 1000 mV. So, if I have 2 V, I have 2000 mV. Below are some examples. Calculate your value, and then mouse over the black box to see if you are correct.
Formulas | ||
mV / 1000 = V V * 1000 = mV |
Examples | ||
2500 mV = 2.5 V 500 mV = 0.5 V 50 V = 50,000 mV 350 mV = 0.35 V |
Let's say that I have 1000 Amps. This would be displayed as 1000 A. We know from the table above that kilo means 1000. So, 1000 A = 1 kA or 1 kiloamp. Below are more examples. Calculate your value, and then mouse over the black box to see if you are correct.
Formulas | ||
A / 1000 = kA kA * 1000 = A |
Examples | ||
1500 kA = 1,500,000 A 1500 A = 1.5 kA 17.3 kA = 17,300 A |
Let's talk about milliamps or mA. From the chart, we see that a milliamp is 1/1000 of an amp. This means that for every amp, I have 1000 mA. So, if I have 2 A, I have 2000 mA. Calculate your value, and then mouse over the black box to see if you are correct.
Formulas | ||
A * 1000 = mA mA / 1000 = A |
Examples | ||
1 A = 1000 mA 20 mA = 0.020 A 4 mA = 0.004 A 50 A = 50,000 m 50 mA = 0.050 A 100 mA = 0.10 A |
Let's say that I have 1000 ohms. This would be displayed as 1000 Ω. We know from the table above that kilo means 1000. So, 1000 Ω = 1 kΩ or 1 kiloohm. Below is more kΩ examples. Calculate your value, and then mouse over the black box to see if you are correct.
Formulas | ||
Ω / 1000 = kΩ kΩ * 1000 = Ω |
Examples | ||
2 kΩ = 2000 Ω 500 Ω = 0.5 kΩ 50 kΩ = 50,000 Ω |
From the chart, we see that a megaohm is 1,000,000 x 1 Ω. This means that for every 1 MΩ, I have 1,000,000 Ω. So, if I have 2 MΩ, I have 2,000,000 Ω. Below are some examples of MΩ. Calculate your value, and then mouse over the black box to see if you are correct.
Formulas | ||
Ω * 1,000,000 = MΩ kΩ * 1000 = MΩ MΩ/ 1,000,000 = Ω MΩ/1000 = kΩ |
Examples | ||
1.5 MΩ = 1,500 kΩ = 1,500,000 Ω 0.5 MΩ = 500 kΩ = 500,000 Ω 0.75 MΩ = 750 kΩ = 750,000 Ω |
Common units for power are watts (W), kilowatts (kW), and megawatts (MW).
Let's say that I have 1000 Watts. This would be displayed as 1000 W. We know from the table above that kilo means 1000. So, 1000 W = 1 kW or 1 kilowatt. Below are more examples. Calculate your value. and then mouse over the black box to see if you are correct.
Formulas | ||
W / 1000 = kW kW * 1000 =W |
Examples | ||
15 kW = 15,000 W 1 kW = 1000 W 1500 W = 1.5 kW |
From the chart, we see that a megawatt is 1,000,000 x 1 W. This means that for every 1 MW, I have 1,000,000 W. So, if I have 2 MW, I have 2,000,000 W. Below are some examples of MW. Calculate your value, and then mouse over the black box to see if you are correct.
Formulas | ||
W * 1,000,000 = MW kW* 1000 = MW MW/ 1,000,000 = W MW/1000 = kW |
Examples | ||
1 MW = 1000 kW = 1,000,000 W 500,000 W = = 500 kW = 0.5 MW 0.01 MW = 10 kW = 10,000 W |
The unit for frequency is hertz or Hz. Units for Hz are typically in Hz or kHz. Below are some examples, as well as formulas, for how to change units. Calculate your value, and then mouse over the black box to see if your correct.
Formulas | ||
Hz /1000 = kHz kHz * 1000 = Hz |
Examples | ||
1000 Hz = 1 kHz60 Hz = 0.06 kHz |
Common units for time are seconds (sec), milliseconds (msec) or microseconds (µsec). Below are some examples. Calculate your value, and then mouse over the black box to see if you are correct.
Formulas | ||
sec * 1000 = msec msec / 1000 = sec |
Examples | ||
1 sec = 1000 msec 500 msec = 0.5 sec 5000 msec = 5 sec |
Formulas | ||
sec *1,000,000 = µsec µsec / 1,000,000 - sec msec * 1000 = µsec µsec / 1000 = msec |
Examples | ||
2 sec = 2000 msec = 2,000,000 µsec 500 µsec = 0.5 msec = 0.005 sec |
Another way to calculate units is by shifting the decimal place. To go from standard units to kilo, you move the decimal 3 places to the left. To return from kilo back to standard, you move 3 places to the right. For example, If you have 1000.0 W, move decimal 3 places to the left to get 1 kW.
Select from the drop-down box to see units and the number of decimal places moved.
Unit | Move |
---|---|
Kilo | 3 deicmal places |
Mega | 6 decimal places |
milli | 3 decimal places |
micro | 6 deicmal places |
To move from kilo to mega, the difference between 6 and 3 is 3. Therefore, you only have to move 3 decimal places.
Another method for switching units is using the exponent. The exponent is the original number multiplied by 10 to the exponent. For example, 1 kΩ x 103 = 1000 Ω.
Below is a table of exponents used to change units.
Unless specified otherwise, any and all work on this page is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.