It depends how you define it, by VESTS or by Steem Power.

Whoever did the original classification used vests, not steem power. That's what @steemchiller implemented in SDS, so I did the same. Back in 2016, 5k steem power was a decent estimate for 10 million vests, which is why people started using that standard. 7 years later, the conversion factor has drifted a bit.

The exact conversion factor is always changing due to blockchain inflation, but can be obtained from any block explorer. SteemDB currently shows it is 570.142 SP per MVEST (million vests), so the cutoff now would be 5701.42 SP under the VESTS definition given above.