Megahertz to terahertz: a million to one, and why it matters
What this conversion does
It divides by a million, which is two full steps of the SI prefix ladder. Almost every frequency a person meets in daily life, from mains power to a mobile phone, converts to a terahertz value so small that it is best written with an exponent. That is not a defect of the tool; it is what the units are telling you about the scale of the spectrum.
The ladder between the two units
Megahertz to gigahertz is one step of a thousand, gigahertz to terahertz is another, so the total is a million. The prefixes were chosen so that each step matches a change of instrument: oscillators and antennas below, waveguides and then optical elements above. Terahertz is the first rung where the equipment stops being electronic, which is why the gap feels larger than the arithmetic suggests.
Megahertz to terahertz conversion table
A walk up the prefix ladder in one column of figures, showing how quickly the terahertz values shrink towards zero.
| Megahertz (MHz) | Terahertz (THz) |
|---|---|
| 1 | 0.000001 |
| 10 | 0.00001 |
| 88.5 | 0.0000885 |
| 100 | 0.0001 |
| 900 | 0.0009 |
| 2400 | 0.0024 |
What lives at the bottom of the table
A broadcast transmitter, a mobile handset and a microwave oven all sit so far below one terahertz that their values are written as tiny decimals with leading zeroes. This is precisely why no engineer quotes them in terahertz: the unit is not wrong, it is simply sized for a different part of the spectrum, and using it for a radio station would add six decimal places and no information.
Count the rungs, not the zeroes
From megahertz to terahertz is two steps of a thousand, so the answer is the input shifted six decimal places. A million megahertz is one terahertz; ten megahertz is one hundred-thousandth of one, or 0.00001.
Frequently asked questions
How do I convert megahertz to terahertz?
Divide by a million. So 1,000,000 MHz is exactly 1 THz, and 100 MHz is 0.0001 THz. The operation is two successive divisions by a thousand, corresponding to the two prefix steps between the units.
How many megahertz are in a terahertz?
One million. The prefix ladder goes kilohertz, megahertz, gigahertz, terahertz, with each rung a factor of a thousand, so terahertz is three rungs above kilohertz and two above megahertz.
Why are ordinary radio frequencies ever written in terahertz?
Usually they are not, and when they are it is for comparison — a table that spans the whole spectrum needs one unit throughout. The values become small decimals, which is the honest representation of where radio sits relative to the top of the usable spectrum.
Does the result lose precision?
No. The division is exact for any input, and results that would be written with many leading zeroes are shown in exponent form so that the significant digits remain visible. The number returned is the true quotient, not a rounded one.
Is a terahertz the same as a trillion hertz?
Yes. One hertz is one cycle per second, so one terahertz is a trillion cycles per second. In megahertz that same frequency is a million, since trillions and millions differ by the two steps of a thousand between them.