Chained Formulas

Formulas can reference cells that hold plain numbers, but they can just as happily reference cells that hold other formulas:

A1: 5
B1: =A1*2
C1: =B1+10

Here C1 references B1, and B1 is itself a formula. No problem: C1 simply uses B1's result. With 5 in A1, B1 shows 10 and C1 shows 20. You've built a chain: A1 → B1 → C1.

Chains make updates ripple. Change A1 to 12 and B1 recalculates to 24, which nudges C1 to recalculate to 34. One edit, and every downstream formula follows, in the right order, automatically. You never have to tell Excel what to compute first, it reads the dependencies and figures it out.

This is how big spreadsheets stay manageable: each formula does one small step, and the steps link up. A subtotal feeds a total, the total feeds a report, every cell simple, the whole thing powerful. One caution: a formula must never reference its own cell (directly or through the chain), that's a circular reference, and Excel will complain.