Live planning model
Solve the deposit that funds your move date
Separate money already saved, money that is contractually expected, and the monthly stream you control. The model grows today’s balance, treats monthly deposits as an ordinary annuity, and tests your own proposed amount.
| Funding line | Entered or solved amount | Future-value factor | Move-date value or difference |
|---|
Current calculation process
Formula, default substitution, intermediate quantities, and check
PMT = max(0, G - R - C(1+r)^n) / [((1+r)^n - 1) / r]
G is the move-date goal, R the confirmed reimbursement, C current savings, r the monthly yield, n the number of deposits, and PMT the required end-of-month contribution.
Use it in five deliberate steps
Build a move fund you can audit
- Set the protected move-date target from written estimates, deposits, travel, temporary housing, and a cash reserve.
- Enter only cash already dedicated to the move as current savings.
- Record reimbursement only when the amount and eligibility are documented; uncertain support belongs in a separate scenario.
- Choose the exact count of end-of-month deposits and a conservative savings-account yield.
- Compare your planned deposit with the solved requirement, then save the current ledger and evidence.
Five funding concepts
What changes the monthly requirement
Goal date matters
The same dollar gap requires larger deposits when fewer monthly periods remain.
Timing is explicit
Deposits occur at month end. A beginning-of-month plan would earn one extra period and needs a different factor.
Current cash compounds separately
Today’s balance receives all entered months of growth; monthly deposits receive progressively fewer months.
Reimbursement is not savings
Keeping it separate makes the plan easy to rerun if an employer changes eligibility or payment timing.
Zero yield is valid
At zero yield, the annuity factor becomes exactly the number of deposits and avoids division by zero.
Symbols and default substitution
Read the equation before trusting the card
| Symbol | Meaning | Default | Unit |
|---|---|---|---|
| G | Protected move target | 12,500 | USD at move date |
| C | Current move savings | 4,200 | USD today |
| R | Confirmed reimbursement | 1,000 | USD at move date |
| r | Monthly yield | 3.5% / 12 | decimal per month |
| n | Deposit periods | 8 | months |
| PMT | Required end-of-month saving | solved | USD per month |
Default substitution: PMT = [12,500 - 1,000 - 4,200(1 + 0.035/12)^8] / [((1 + 0.035/12)^8 - 1)/(0.035/12)]. The live process preserves unrounded factors and reconciles the result back to the goal.
Three planning lenses
Use the result as a decision, not a promise
Reimbursement stress test
Rerun with reimbursement at zero. The difference in required monthly saving is the plan’s reliance on employer support.
Liquidity boundary
Do not count security deposits or emergency cash twice. A move target should include any minimum reserve that must remain untouched.
Calendar compression
If the move advances, reduce the deposit count rather than pretending the same monthly amount has more time to work.
Two contrasting cases
Normal and boundary decisions
Eight-month interstate move
A household with $4,200 saved, $1,000 documented support, and a $12,500 goal uses the default run to set an automatic monthly transfer and retains the PDF with the employer letter.
Goal already funded
If current savings grown to the move date plus confirmed reimbursement already exceed the target, required monthly saving is zero. The planned-deposit card then shows optional cushion, not a required payment.
Terms
Moving-fund vocabulary
- Protected target
- The move-date amount including any reserve intentionally preserved.
- Ordinary annuity
- Equal deposits made at the end of each period.
- Future value
- What current or periodic savings become at the move date.
- Nominal annual yield
- The annual rate divided by 12 in this monthly model.
- Funding gap
- The goal remaining after future current savings and confirmed support.
- Reconciliation
- Adding every future-value funding line back to the protected target.
Questions specific to a move fund
Frequently asked questions
Should I include an expected employer reimbursement?
Include it only when the amount, eligible expenses, and timing are documented. Otherwise run a second case with reimbursement set to zero.
Why are deposits treated as end-of-month?
The equation uses an ordinary annuity. If you deposit at the beginning of every month, this result is conservative because your money receives more time to earn.
What happens when I enter a zero yield?
The model uses the exact zero-rate limit: the savings-stream factor equals the number of deposits. No interest is assumed.
Can the required monthly amount be negative?
No. When existing resources already fund the goal, the required contribution is reported as zero and any planned saving appears as cushion.
Should emergency savings count as current move savings?
Only the portion you are genuinely willing to spend. If an emergency reserve must remain intact, include that protection in the target or leave the reserve out of current savings.
How often should I rerun the plan?
Rerun it after a written estimate changes, the move date shifts, reimbursement terms change, or an actual monthly deposit differs from plan.
Limits, evidence, and disclaimer
What this savings model does not know
- Yield may change and the model does not estimate tax on interest.
- Deposits are assumed to arrive at month end; irregular pay dates require a cash-flow schedule.
- Reimbursement timing, eligibility, and tax treatment are outside the formula.
- The target is only as complete as the mover estimates, accessorial services, travel, housing overlap, and reserve entered upstream.
Evidence record: retain written mover estimates, inventory, reimbursement terms, account statements, target worksheet, and the exported current-value report. This calculator provides planning mathematics, not financial advice or a guarantee of return.
Reliable starting points
Sources and related planning
- CFPB: Your Money, Your Goals toolkit — savings goals and cash-flow tools.
- FMCSA: Steps to select a mover — written estimates and mover checks.