# How to define UInt256?

**URL:** <https://discourse.julialang.org/t/how-to-define-uint256/104688>\
**Category:** General Usage\
**Created:** [October 7, 2023, 4:12am UTC](https://discourse.julialang.org/t/how-to-define-uint256/104688 "2023-10-07T04:12:26Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![tomtom](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tomtom/32/5106_2.png) [@tomtom](https://discourse.julialang.org/u/tomtom)\
**Post date:** [October 7, 2023, 4:12am UTC](https://discourse.julialang.org/t/how-to-define-uint256/104688/1 "2023-10-07T04:12:26Z")

</div>

is there an efficient way to define a “big” unsigned integer type like UInt256?

what things should I implement?

don’t wanna use BigInt.

thanks

---

<div class="post-metadata">

**Author:** ![Oscar\_Smith](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/oscar_smith/32/25343_2.png) [@Oscar\_Smith](https://discourse.julialang.org/u/Oscar_Smith)\
**Post date:** [October 7, 2023, 5:26am UTC](https://discourse.julialang.org/t/how-to-define-uint256/104688/2 "2023-10-07T05:26:28Z")

</div>

A;ready made for you in [GitHub - rfourquet/BitIntegers.jl: Fixed-width integers similar to builtin ones](https://github.com/rfourquet/BitIntegers.jl).

---

<div class="post-metadata">

**Author:** ![tomtom](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tomtom/32/5106_2.png) [@tomtom](https://discourse.julialang.org/u/tomtom)\
**Post date:** [October 7, 2023, 5:53am UTC](https://discourse.julialang.org/t/how-to-define-uint256/104688/3 "2023-10-07T05:53:36Z")

</div>

thanks!