A broad rule of thumb these days is that a worldwide box office take of around 2.5X the production budget will make a sequel a no-brainer (unless domestic box office is especially weak and/or there's some behind the scenes troubles). So a worldwide box office take of around $450-460 million is the target for STiD
. 3X the production budget - around $540-550 million - and they'll be doing cartwheels.
2X the production budget, while disappointing, can still lead to a sequel if DVD/Blu-ray sales are especially strong and if the box office is tilted towards domestic box office, but that sort of return will usually lead to cost-cutting and re-engineering.