How to Convert Nanometers to Meters

nm to m Worked Unit Conversion Example Problem

Red laser
Nanometers are used to express wavelength of light. artpartner-images / Getty Images

This example problem demonstrates how to convert nanometers to meters or nm to m units. Nanometers are a unit most commonly used to measure wavelengths of light. There are one billion nanometers (109) in one meter.

Nanometers to Meters Conversion Problem

The most common wavelength of the red light from a helium-neon laser is 632.1 nanometers. What is the wavelength in meters?

Solution:

1 meter = 109 nanometers

Set up the conversion so the desired unit will be cancelled out.

In this case, we want m to be the remaining unit.

distance in m = (distance in nm) x (1 m/109 nm)
Note: 1/109 = 10-9
distance in m = (632.1 x 10-9) m
distance in m = 6.321 x 10-7 m

Answer:

632.1 nanometers is equal to 6.321 x 10-7 meters.

Meters to Nanometers Example

It's a simple matter to convert meters to nanometers using the same unit conversion.

For example, the longest wavelength of red light (almost infrared) that most people can see is 7.5 x 10-7 meters. What is this in nanometers?

length in nm = (length in m) x (109 nm/m)

Note the meters unit cancels out, leaving nm.

length in nm = (7.5 x 10-7) x (109) nm

or, you could write this as:

length in nm = (7.5 x 10-7) x (1 x 109) nm

When you multiply powers of ten, all you need to do is add together the exponents. In this case, you add -7 to 9, which gives you 2:

length of red light in nm = 7.5 x 102 nm

This may be rewritten as 750 nm.

Quick Tips for Nanometers to Meters Conversion

  • Remember, if you're working with exponents, you simply add "9" to the meters value to get the answer in nanometers.
  • If you write the number out, move the decimal point nine places to the left to convert nanometers to meters or to the right to convert meters to nanometers.