| The converter returns an unexpected number | Source and destination units may be reversed or the input may use radians when degrees were intended. | Check both dropdowns and the displayed formula; test a reference such as 180° = π rad before proceeding. |
| The pi expression is rejected | The typed expression may not match supported notation or may include unsupported operators. | Try a documented example such as pi/2 or 2pi and remove extra characters before retrying. |
| Decimal result differs slightly between calculators | Different programs round π or use different formatting precision. | Compare unrounded values where possible and distinguish a small rounding difference from a wrong conversion factor. |
| The result contains too many decimal places | Automatic display may retain more figures than the report needs. | Use the 0–15 decimal-place control and round to the real accuracy of the underlying measurement. |
| Tiny angles display as zero | Display precision can round a small nonzero result to zero. | Select additional decimal places or scientific notation and inspect the underlying unit. |
| A large angle is displayed in scientific notation | Magnitude or the selected notation setting can trigger exponential display. | Switch to Standard notation when appropriate, or retain scientific notation with a clearly labeled unit. |
| Trig tangent shows infinity or an extreme number | The angle may be at or close to a cosine-zero singularity such as 90°. | Treat exact singularities as undefined and inspect sine and cosine rather than trusting an extreme tangent value. |
| Sine of 180 degrees is not printed as exact zero | Floating-point evaluation of π can leave a tiny residual. | Apply a justified numerical tolerance and use the exact trigonometric identity for symbolic mathematics. |
| A 90-degree angle appears clockwise instead of counterclockwise | The reference diagram or external software may use screen coordinates or another sign convention. | Confirm orientation axes and positive rotation direction before comparing the images. |
| Azimuth and quadrant bearing disagree | An input may be measured from east rather than north or counterclockwise instead of clockwise. | Use standard clockwise-from-north azimuth and verify with N45°E = 45°. |
| Compass direction seems off by one sector | 16-point labels are spaced 22.5° apart, while traditional 32-point angular units are 11.25°. | Identify whether the task requests a 16-point heading label or a numerical 32-point compass-unit conversion. |
| A magnetic compass heading does not match converted azimuth | Angular notation conversion does not automatically include local magnetic declination. | Determine the required true, magnetic or grid north reference and apply an independently verified correction if needed. |
| NATO mil result differs from milliradians | A NATO mil uses 6400 parts per turn, while mrad uses 1000 parts per radian. | Select the exact unit label and avoid treating generic mil as synonymous with mrad. |
| Two military mil references disagree | A reference may use 6000, 6300 or 6400 divisions per turn. | Specify the Warsaw Pact, Swedish or NATO standard before using the conversion. |
| Slope percent looks larger than the angle | Percent grade is tangent times 100, not the numerical degree value. | Verify with 45° = 100% and state that run means horizontal distance. |
| A vertical slope does not yield a finite grade | As slope approaches 90°, horizontal run tends to zero and tangent diverges. | Describe the geometry directly rather than treating vertical grade as a finite percent. |
| A 10 percent slope was entered as 10 degrees | Grade and angle are different measurements. | Use inverse tangent of 0.10 to obtain approximately 5.71 degrees instead of entering 10°. |
| Radians from code do not match degrees from a design file | A programming math function may expect radians while the drawing supplies degrees. | Convert explicitly with degrees × π/180 and write the unit next to variables. |
| The converted angle exceeds 360 degrees | The input may represent multiple complete turns rather than an orientation. | Normalize only if a single-turn direction is needed; otherwise preserve cumulative rotations. |
| Negative angle normalizes to a different positive number | Modulo conventions and chosen interval affect the normalized representative. | Use a clearly specified interval such as [0°, 360°) and test −90° → 270°. |
| Arcminutes are confused with minutes of time | The same word minute can refer to angular subdivision or clock time. | Use prime symbols for angular measurements and time-angle units only where specifically intended. |