Convert m to nm metres ↔ nanometres Free Online Secure
Type a value in metres and read it in nanometres at once. The factor is exact by definition, the arithmetic happens in your browser, and nothing is sent anywhere.
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Common values — Convert m to nm (metres ↔ nanometres)
| m | nm |
|---|---|
| 1 | 1000000000 |
| 2 | 2000000000 |
| 3 | 3000000000 |
| 5 | 5000000000 |
| 10 | 10000000000 |
| 20 | 20000000000 |
| 50 | 50000000000 |
| 100 | 100000000000 |
Where these units come from
The metre was first defined in 1793 as a ten-millionth of the distance from the equator to the North Pole — a definition nobody could check without surveying a quarter of the planet. It has been redefined four times since, each time to something steadier: a platinum bar, then a prototype kept in Paris, then a wavelength of krypton light, and since 1983 the distance light travels in vacuum in 1/299,792,458 of a second. The inch stopped being a separate thing in 1959, when six countries agreed to define it as exactly 25.4 mm. That agreement is why every conversion on this page between a metric and an imperial length is exact rather than measured: both sides now descend from the same definition.
Where you meet them
Millimetres are the working unit of engineering drawings and of anything made in a workshop; centimetres belong to tailoring, furniture and school rulers; metres to rooms, fabric and running tracks. Feet and inches survive in aviation altitudes worldwide, in American and British construction, and in the diagonal of every screen you have ever bought. Nautical miles are not a quaint survival — one is a minute of latitude, which is why ships and aircraft still navigate in them.
Questions people ask
How is the metre defined today?
As the distance light travels in a vacuum in 1/299,792,458 of a second. The definition has been in place since 1983 and ties the metre to the speed of light, which is itself fixed at exactly 299,792,458 metres per second. The old platinum bar in Paris no longer defines anything.
How small is a nanometre?
A nanometre is a billionth of a metre. Visible light has wavelengths of roughly 400 to 700 nanometres, and a human hair is about 80,000 nanometres across. You meet the unit wherever things are too small to see: wavelengths of light, the thickness of coatings, the size of viruses and the features of microchips.
Is the answer exact?
Where both units are defined in terms of one another by whole numbers, yes — the page says so above the figure, and the only rounding is in how many digits are shown. Where the ratio has no finite decimal, the page shows twelve significant digits and says the relation is approximate rather than pretending otherwise.
Does anything I type leave my device?
No. The arithmetic runs in your browser; nothing is uploaded and there is no server to upload it to. Load the page once and it keeps working with the network switched off.
From a metre to a billionth of one: how to convert m to nm
It takes a billion nanometres to make a metre, a ratio so large that few people ever have to cross it in one step. Yet it happens in physics classes, in articles on microchips, in discussions of light and in any text that compares human size with the scale of atoms. A metre stick, a wavelength of green light and the width of a virus can all sit in one table, and to read them side by side you have to convert m to nm. This page does it as you type and shows the result in full and in scientific notation.
The rule is a multiplication by one billion, which moves the decimal point nine places to the right. The result is exact, but the numbers are very large, and scientific notation is often the clearest way to write them. The sections below give the rule with examples, say what each unit is, compare them, look at where the conversion matters in science and technology, and list the mistakes that creep in.
How to convert m to nm: multiply by 1,000,000,000
The rule
One metre is 1,000,000,000 nanometres, or 10 to the ninth power. To convert m to nm, multiply the number of metres by one billion, or move the decimal point nine places to the right. 1 m is 1e9 nm, 2.5 m is 2.5e9 nm, 0.001 m is 1e6 nm and 0.0000005 m is 500 nm. In the reverse direction, divide by one billion.
Examples
Green light has a wavelength of 0.00000055 m, which is 550 nm. A human hair is about 0.00007 m, 70,000 nm. A virus of 0.0000001 m is 100 nm. A DNA double helix is 0.000000002 m, 2 nm across. A metre stick, 1 m, is a billion nanometres long.
Counting zeros
Instead of moving the point nine places, count in groups of three: metre to millimetre is three places, to micrometre six, to nanometre nine. A length written as 3.2 micrometres is 3,200 nm. That route avoids the big jump and uses the metric ladder.
Scientific notation
Write the answer as a number between 1 and 10 times a power of ten. 0.00000055 m is 5.5e-7 m, and in nanometres it is 550, or 5.5e2. This notation helps with the very large and the very small and is supported by every calculator and spreadsheet.
The metre
The base unit
The metre is the SI base unit of length. Defined since 1983 by the speed of light, it is the distance light travels in 1/299,792,458 of a second. It is the right unit for everyday objects, from a ruler to a road.
Why not for atoms
Atoms and molecules are billions of times smaller than a metre. Writing their size in metres produces numbers with nine or more zeros after the decimal point. That is why science moved to prefixes: micro, nano and pico.
The nanometre
A billionth of a metre
The nanometre is one billionth of a metre. The prefix nano comes from the Greek for dwarf. A nanometre is about the length a fingernail grows in a second. The symbol is nm.
Where it is used
Wavelengths of light, the feature sizes of microchips, the thickness of coatings and the size of viruses and large molecules are all quoted in nanometres. The visible spectrum runs from about 380 to 750 nm.
Metre and nanometre compared
A metre is a billion nanometres. If a nanometre were the size of a marble, a metre would be about 10,000 kilometres long. Because of this scale gap, you rarely use both units in one sentence except to illustrate it.
Use metres for everyday objects, millimetres or micrometres for small devices and nanometres for molecules and light. When a text mixes them, state the unit with every figure and, if possible, add a scientific-notation version.
Where you will need it
Light and colours
Visible light spans 380 to 750 nm. In metres, that is 3.8e-7 to 7.5e-7. Red laser pointers emit at 650 nm, green at 532 nm, blue at 450 nm. Fibre-optic telecoms use 1,310 and 1,550 nm. Physics formulas require metres, so a “convert m to nm” calculation is the first step in almost every optics problem.
Microchips
Chip makers describe their processes in nanometres: 7 nm, 5 nm, 3 nm. These are marketing labels rather than exact feature sizes, but the real dimensions are tens of nanometres. A transistor gate of 20 nm is 2e-8 m, a hundred times thinner than a bacterium.
Biology and medicine
A virus is 20 to 300 nm, a bacterium 1,000 to 5,000 nm, a red blood cell about 7,000 nm. The coronavirus is about 100 nm. In metres these are 1e-7, 1e-6 to 5e-6 and 7e-6. A table in nanometres gives whole numbers that are easier to compare.
Coatings and films
An anti-reflective coating on glass is about 100 nm thick, 1e-7 m. A soap bubble wall is around 300 nm. Gold leaf is 100 nm. Engineers specify film thickness in nanometres because the colour of thin films depends on it.
Atoms and molecules
The size of the small
A hydrogen atom has a diameter of about 0.1 nm, 1e-10 m. A water molecule is about 0.3 nm. Glucose is 0.9 nm. A protein is 5 to 10 nm. DNA's width is 2 nm. Counting these in metres leads to tiny numbers; nanometres give figures that are easy to read.
Counting atoms in a metre
A metre of atoms laid side by side, at 0.25 nm each, would hold four billion atoms. The calculation uses the “convert m to nm” calculation step: 1 m is 1e9 nm; divided by 0.25 gives 4e9.
Mental arithmetic with prefixes
Group by thousands
Because the prefixes step by 1,000, you can read a length straight from its position. 0.000 000 550 m, written in groups of three, reads as 550 nm: the group after the six zeros is the nanometre value. Spaces between groups help the eye.
Check with orders of magnitude
A result in nanometres for an object you can see should be at least 1e5, that is 100,000 nm, since the smallest thing visible to the naked eye is about 0.1 mm. If you get 50 nm for a pencil, something is wrong.
Light travel in nanometres
The wavelength and the frequency
Light has a frequency equal to the speed of light divided by wavelength. A wavelength of 550 nm, 5.5e-7 m, gives 5.45e14 hertz. Converting the wavelength to metres is the first step in this calculation, and the reverse is used when a radio engineer wants to describe the wave in nanometres.
Photon energy
The energy of a photon is 1,240 divided by the wavelength in nanometres, giving electronvolts. At 550 nm, 2.25 eV; at 400 nm, 3.1 eV. This handy formula requires nanometres.
Thin film interference
Colours of soap bubbles
A soap film shows colour when its thickness is a fraction of a wavelength, from around 100 to 500 nm, 1e-7 to 5e-7 m. Oil on water shows rainbow bands at thicknesses between 200 and 1,000 nm.
Anti-reflective coatings
The coating on glasses is one quarter of a wavelength thick, which for green light is 137 nm in a medium of refractive index 1. Designers need convert m to nm for every layer they specify.
Scale models of the small
A model that fits a room
If a hydrogen atom were a marble of 1 cm, the nucleus would be a speck a tenth of a micrometre wide, and a metre would stretch about 100,000 kilometres. The comparison shows that ordinary lengths are, in atomic terms, enormous.
The ratio
One metre divided by one nanometre is a billion, the number of seconds in 31.7 years. A billion nanometres in a metre is a manageable idea when you think of a billion seconds as a human lifetime of 32 years.
A worked example
The thickness of a coating
A coating on a lens is specified as 0.000000102 m. To convert m to nm, multiply by 1e9: 102 nm. The designer wanted a quarter wave at 550 nm in glass of index 1.35, which is 550 divided by 4 divided by 1.35, equal to 102 nm. The numbers agree, so the coating is as intended.
Why show both
The supplier's data sheet gave the thickness in metres; the design file used nanometres. Checking one against the other in a quick conversion avoided a wrong test order that would have cost days.
Final checks
Three questions
After converting, ask whether the answer has nine more places than the metre figure, whether it matches the expected order of magnitude and whether it agrees with an independent estimate. If all three hold, the conversion is sound.
Documenting
State both the metre and nanometre figures in your notes, together with the exponent. A later reader can then see exactly how you moved from one unit to the other.
Reading a datasheet
Mixed units on one page
A datasheet for an optical filter may state the substrate thickness as 2 mm, the coating as 450 nm and the clear aperture as 0.025 m. To compare the three you must convert m to nm, or bring the other two into metres: 0.002, 4.5e-7 and 0.025. In nanometres, the figures are 2,000,000; 450; and 25,000,000. The coating is thousands of times thinner than the glass, which is why it does not change the filter's shape but only its colour.
Why the unit shifts
Manufacturers choose the unit in which the number is easiest to read for each item. Do not assume a single unit across the whole sheet; read the label beside every number.
Nanotechnology in daily life
Products you meet
Sunscreens use zinc oxide particles of 20 to 100 nm. Self-cleaning glass has a titanium dioxide coating of 15 nm. Stain-resistant fabrics carry nanoscale coatings. Screens use quantum dots of 2 to 10 nm to produce pure colours.
Safety discussions
Regulators discuss particles below 100 nm because they behave differently from larger ones. Reports quote sizes in nanometres, and a reader who wants to compare with a hair or a cell may need to convert.
The fingernail and the continent
Slow things
A fingernail grows about 3 mm a month, 1.2 nm per second. Continents drift at 2 to 5 cm a year, which is 0.6 to 1.6 nm per second. These comparisons show what a nanometre means in real time.
Another way to see it
If your hair grows 0.4 mm a day, it grows 4.6 nm each second. In a minute, that is 277 nm, about half the wavelength of green light.
Spectroscopy and colour
Reading a spectrum
Spectrometers plot intensity against wavelength in nanometres. Sodium streetlamps emit at 589 nm. Hydrogen's red line is at 656 nm. Mercury emits at 254 nm in the ultraviolet. A student measuring with a ruler in metres on a diffraction grating converts the answer to nanometres at the end.
Why nanometres
Wavelengths of visible light in metres are 0.00000038 to 0.00000075, awkward to write. In nanometres they are 380 to 750, with no decimals.
Metrology and standards
Precision in manufacturing
High-precision optics are polished to a surface flatness of a fraction of a wavelength, about 10 to 50 nm. A mirror for a space telescope may be accurate to 20 nm over a diameter of 6.5 m, a ratio of 3e-9. Converting the diameter to nanometres, 6.5e9 nm, shows the ratio clearly.
Calibration
Laboratories calibrate length standards using interferometers that count light waves of known wavelength, such as 633 nm helium-neon laser light. One metre contains 1.58 million of these wavelengths.
Spreadsheets and big numbers
Formula
To convert m to nm for a column, put metres in column A and enter =A2*1E9 in column B. Format in scientific notation with three decimals for very large values, or as a number with separators for values below a trillion. To reverse, divide by 1E9.
Floating-point precision
Spreadsheets hold about 15 significant digits, so there is no problem with nine zeros. But subtracting two nearly equal large numbers can lose precision, so do arithmetic in the original unit and convert the result.
Precision and rounding
Match the data
A wavelength known to three figures, 550 nm, has an uncertainty of about 0.5 nm. Writing 550.000 nm would be wrong. If you convert from 5.50e-7 m, keep three figures: 550 nm.
Significant figures
When you multiply by 1e9, the number of significant figures does not change. 0.0000012 m has two significant figures; 1,200 nm also has two, although it looks like four digits. Write 1.2e3 nm to make it clear.
History of the prefix
Nano enters the metric system
The prefix nano was adopted in 1960 by the General Conference on Weights and Measures along with pico and others. It comes from the Greek nanos, dwarf. The prefixes for 10 to the minus nine and minus twelve filled in the gaps below micro.
Nanotechnology as a word
The term nanotechnology was coined by Norio Taniguchi in 1974 and popularised by Eric Drexler in the 1980s. Today it covers science at scales of 1 to 100 nm.
Teaching powers of ten
A ladder with a long reach
To convert m to nm step by step, draw the metric ladder down from the metre: millimetre (1e-3), micrometre (1e-6), nanometre (1e-9). Each rung is a factor of one thousand. To move from metres to nanometres you take three steps, each a multiplication by 1,000. Students see that the move of nine places is three groups of three.
Everyday examples
Ask pupils to place a hair, a bacterium, a virus and an atom on the ladder. A hair is at 1e-4 m, a bacterium at 1e-6, a virus at 1e-7 and an atom at 1e-10. The ladder becomes a map of the small world.
More values for convert m to nm
A longer list of conversions
If the value you need is not in the first list, these further conversions may be close enough to read off directly:
- 0.1 m = 100,000,000 nm
- 0.5 m = 500,000,000 nm
- 3 m = 3,000,000,000 nm
- 4 m = 4,000,000,000 nm
- 7 m = 7,000,000,000 nm
- 15 m = 15,000,000,000 nm
- 20 m = 20,000,000,000 nm
- 75 m = 75,000,000,000 nm
- 200 m = 200,000,000,000 nm
- 500 m = 500,000,000,000 nm
- 2,000 m = 2,000,000,000,000 nm
- 10,000 m = 10,000,000,000,000 nm
Mistakes when you convert m to nm
Moving six places instead of nine
That gives micrometres. For nanometres, nine places.
Dividing instead of multiplying
Nanometres are smaller, so the number grows. If 0.0000005 m becomes 5e-16, you divided.
Confusing nano with micro
A micrometre is a thousand nanometres. Always check which prefix a source uses.
Quick answers
How many nanometres in a metre?
One billion.
How do I convert m to nm?
Multiply by 1,000,000,000.
What is 0.0000005 m in nanometres?
500 nm.
Is the conversion exact?
Yes, exact.
Does my number leave my device?
No. The calculation runs in your browser.
Related pages and a last word
If you work with lengths, these conversions are close at hand: Convert m to dm, Convert m to km, Convert °C to °F, Convert °F to °C, Convert L to gal, Convert gal to L, Convert tsp to tbsp, Convert L/100km to MPG (US), Convert acres to ha. The reverse of this page is Convert nm to m.
In short, to convert m to nm multiply by a billion, move the decimal point nine places to the right, use scientific notation for clarity and keep only the digits your measurement supports. Your number stays on your device: nothing is uploaded and no account is needed.