---
title: ulpOfOne
framework: swift
role: symbol
role_heading: Type Property
path: swift/float/ulpofone
---

# ulpOfOne

The unit in the last place of 1.0.

## Declaration

```swift
static var ulpOfOne: Float { get }
```

## Discussion

Discussion The positive difference between 1.0 and the next greater representable number. The ulpOfOne constant corresponds to the C macros FLT_EPSILON, DBL_EPSILON, and others with a similar purpose.

## See Also

### Accessing Numeric Constants

- [pi](swift/float/pi.md)
- [infinity](swift/float/infinity.md)
- [greatestFiniteMagnitude](swift/float/greatestfinitemagnitude.md)
- [nan](swift/float/nan.md)
- [signalingNaN](swift/float/signalingnan.md)
- [leastNormalMagnitude](swift/float/leastnormalmagnitude.md)
- [leastNonzeroMagnitude](swift/float/leastnonzeromagnitude.md)
- [zero](swift/float/zero.md)