Frequency from angular frequency calculator
This frequency from angular frequency calculator converts an angular rate, measured in radians per second, into ordinary frequency in hertz.
Run — free
It applies the relationship f = ω/(2π), because one complete cycle contains 2π radians. Enter omega, choose the number of decimal places, and receive the corresponding cycles per second. The calculation is deterministic, works for zero and positive values, and makes the units explicit so that radians per second are not accidentally treated as hertz.
Understand angular frequency and ordinary frequency
Angular frequency and ordinary frequency describe the same repeating motion from different viewpoints. Ordinary frequency, written as f and measured in hertz, counts complete cycles per second. Angular frequency, usually written as the Greek letter omega, measures the phase swept out each second in radians. A complete turn or sinusoidal cycle spans 2π radians, so a system completing one cycle every second has an ordinary frequency of 1 Hz and an angular frequency of approximately 6.283185 radians per second. This distinction appears throughout optics, wave physics, electronics, and harmonic motion. Equations for phase often use expressions such as cos(ωt), while specifications and measurements are commonly reported in hertz. The numerical values are therefore not interchangeable even though they refer to the same oscillation. This calculator keeps the source value visible, labels the result in hertz, and reports the formula used. That makes it useful both for a quick conversion and for checking a longer derivation in which angular notation must be converted back to cycles per second.
Apply f = omega divided by two pi
The conversion has one essential step: divide angular frequency by 2π. If omega is 100 radians per second, the ordinary frequency is 100 divided by 6.283185..., or about 15.915494 hertz. The radian is a dimensionless angular measure, but writing rad/s remains valuable because it signals that the number represents phase advance rather than complete cycles. The calculator accepts a finite nonnegative angular frequency and performs the division using the runtime's value of π. You can select from zero to fifteen decimal places to match the precision appropriate for your data. Rounding happens only after the conversion, which avoids introducing an avoidable intermediate approximation of 2π. A value of zero returns zero hertz, representing no oscillation. Negative angular frequency can carry directional meaning in some advanced conventions, but this calculator targets frequency magnitude and therefore rejects negative input instead of silently changing its sign. Extremely large values are bounded as documented so malformed input cannot produce misleading or unstable output.
Use the result correctly in optics and wave calculations
In optics, angular frequency often appears in field equations, dispersion relations, and photon-energy expressions, while laboratory instruments may display terahertz or hertz. Convert omega to f before inserting the value into a formula that explicitly expects cycles per second. Conversely, do not divide by 2π when the next equation already expects angular frequency; doing so would apply the conversion twice. Unit labels are the safest check: rad/s indicates omega, while Hz means cycles per second. For example, an angular frequency of 2π × 5 × 10^14 rad/s corresponds to 5 × 10^14 Hz, a typical optical-scale frequency. The returned hertz value can then be converted to kilohertz, megahertz, gigahertz, or terahertz if a more readable prefix is needed. Choose output precision based on the precision of the original measurement rather than keeping every displayed digit. The API response also includes the original angular frequency, selected precision, and symbolic formula, making automated records easier to audit and reducing ambiguity when results move between calculation tools, notebooks, and reports.
What you can do with it
Convert an optical angular frequency
Turn a wave model's angular frequency in radians per second into hertz for comparison with a spectrometer or published frequency range.
Check a sinusoidal equation
Translate the omega in a phase expression into cycles per second to verify the period or compare it with measured oscillations.
Normalize engineering data
Convert rad/s values to hertz before storing them alongside datasets and specifications that use ordinary frequency units.
FAQ
What formula converts angular frequency to frequency?
Use f = ω/(2π), where ω is angular frequency in radians per second and f is ordinary frequency in hertz.
Why is angular frequency divided by 2π?
One complete cycle spans 2π radians, so dividing radians per second by radians per cycle gives cycles per second.
Are radians per second the same as hertz?
No. Both describe repetition rates, but rad/s measures phase angle per second and hertz counts complete cycles per second.
Can angular frequency be zero?
Yes. Zero radians per second converts to zero hertz and represents no phase progression or oscillation.
How much does the API calculation cost?
Each API request costs $0.002. The same deterministic calculation can also run free in the browser.
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/optics/frequency-from-angular-frequency \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"angular_frequency":6.283185307179586}'const res = await fetch("https://api.kit.forhosting.com/optics/frequency-from-angular-frequency", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"angular_frequency": 6.283185307179586
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/optics/frequency-from-angular-frequency",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"angular_frequency": 6.283185307179586
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/optics/frequency-from-angular-frequency", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"angular_frequency":6.283185307179586}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"angular_frequency":6.283185307179586}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/optics/frequency-from-angular-frequency", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"angular_frequency": 6.283185307179586
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "optics.frequency_from_angular_frequency",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Limits
max_angular_frequency_rad_s | 1000000000000000 |
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |