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Convert Radians to Turns

1 radian is 0.16 turn. One radian is exactly 0.159154943092 turns.

One radian is 0.15915494 turns. To convert radians to turns, multiply by 0.15915494; to go the other way, divide by 0.15915494 or multiply by 6.2831853. The relation is exact but the figure is not: it is a rounding of a number that does not terminate, and it follows from NIST Special Publication 811. The angle subtending an arc equal to the radius.

Factor checked against the defining standard · How we check

Turns
0.16 turn
Radians × 0.15915494
1 * 0.15915490.159 turn

1 radian in every angle unit

1 radian expressed in every angle unit
UnitValueExact factor
radians (as entered)1 rad—
degrees57.29577951 °× 57.2957795131
gradians63.66197724 gon× 63.6619772368
arcminutes3,437.746771 ′× 3,437.74677078
arcseconds206,264.8062 ″× 206,264.806247
turns0.1591549431 turn× 0.159154943092
milliradians1,000 mrad× 1,000

Factors are entered by hand from NIST Special Publication 811 rather than derived from a units library, so the ones that terminate are exact rather than rounded.

How do you convert radians to turns? The converter and the working

  1. 1.Take the measurement in radians.
  2. 2.Multiply by 0.15915494 — that is how many turns fit in one radian.
  3. 3.To go back the other way, divide by 0.15915494, or multiply by 6.2831853.

Worked example: 25 radians to turns

Formula
rad × 0.15915494 = turn
Arithmetic
25 × 0.15915494 = 3.98 turn
Answer
25 rad = 3.98 turn

The factor is rounded for display; the figure above is computed from the full value.

Radians to turns conversion table

Radians to turns conversion table
RadiansTurns
1 rad0.16 turn
2 rad0.32 turn
3 rad0.48 turn
4 rad0.64 turn
5 rad0.8 turn
6 rad0.95 turn
7 rad1.11 turn
8 rad1.27 turn
9 rad1.43 turn
10 rad1.59 turn
12 rad1.91 turn
15 rad2.39 turn
20 rad3.18 turn
25 rad3.98 turn
50 rad7.96 turn
100 rad15.92 turn
200 rad31.83 turn
300 rad47.75 turn
500 rad79.58 turn
1000 rad159.15 turn
2000 rad318.31 turn
5000 rad795.77 turn
10000 rad1,591.55 turn

What is a radian?

The angle subtending an arc equal to the radius. It is the unit every trigonometric function in every programming language actually takes, which is why a sine computed in degrees comes out wrong.

What is a turn?

One full revolution — 360 degrees, 400 gradians, 2π radians. Gear ratios, threads per turn and rotational counts are all stated in these.

How many turns are in a radian?

One radian is 0.15915494 turns. Going the other way, one turn is 6.2831853 radians. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.

Every angle unit here

The whole group — 7 units with their symbols and the size of each one in radians — is on the conversion index, along with every pair it makes. The table above already gives each of them relative to a radian.

Source: NIST Special Publication 811 — the radian, and units accepted for use with the SI

Cite this page

APA
Rule Calculator. (2026). Convert Radians to turns. Rule Calculator. https://rulecalculators.com/convert/radian-to-turn
MLA
"Convert Radians to turns." Rule Calculator, August 16, 2026, https://rulecalculators.com/convert/radian-to-turn.
Chicago
Rule Calculator. "Convert Radians to turns." Rule Calculator. Last reviewed August 16, 2026. https://rulecalculators.com/convert/radian-to-turn.

The date is when the figures on this page were last checked against their source, not the day you opened it. Add your own access date if your style needs one.

Questions people actually ask

How many turns are in a radian?
0.15915494. One full revolution — 360 degrees, 400 gradians, 2π radians. Gear ratios, threads per turn and rotational counts are all stated in these.
How do I convert turns back to radians?
Divide by 0.15915494, or multiply by 6.2831853 — they are the same operation.

Other angle conversions

Turns to radians — the same conversion the other way.

Calculators that work in angle