You can enter a figure directly into a cash-flow cell instead of relying only on the spread tool. Work from left to right: later months adjust to allocate the remaining amount while earlier months stay unchanged.

Example: adjust a £100,000 build cost

  1. Spread £100,000 evenly across Months 2–5. Each month starts at £25,000.
  2. Change Month 2 to £40,000. The remaining £60,000 is spread across Months 3–5 at £20,000 each.
  3. Change Month 4 to £30,000. Months 2 and 3 stay at £40,000 and £20,000. Month 5 adjusts to £10,000 so the total remains £100,000.
Amounts after each adjustment
StageMonth 2Month 3Month 4Month 5Total
Initial spread£25,000£25,000£25,000£25,000£100,000
Edit Month 2£40,000£20,000£20,000£20,000£100,000
Edit Month 4£40,000£20,000£30,000£10,000£100,000

Use the remaining assignable amount to check what has been allocated and what remains. The same principle applies to an S-curve distribution: review the remaining months after each manual edit.