Actual vs. estimated hours won't tell you the schedule variance, it will tell you a cost variance. For schedule variance you need to know an objective measure of progress.
What information do you have about your tasks and schedule?
I have decades of experience in using Excel and project scheduling tools to do schedule and cost variance analysis, but it's hard to answer your question concretely because it's pretty high-level.
Using Earned Value Management System, you would determine the work that should be complete at a point in time based on your baseline schedule, then determine the work that is actually complete based on progress. So if it costs $1 to make a widget, and you are supposed to make 100 widgets by now and you have only made 80, you have a schedule variance of -$20. It seems odd to express a schedule variance as dollars instead of time, but that actually makes a lot of sense--your productivity is $20 less than it should have been in this amount of time.
If you go strictly by schedule, then you have to look at a breakdown of subtasks and see what's been completed, and you could express a variance in days.
But without knowing more about what you're doing and how you schedule it, I'm not sure how to answer.