📚 Formula & Explanation
How the Tenant Break-Even Calculator works
The goal of a tenant break-even calculation is simple: compare two timelines.
One timeline is “what you pay if you stay.” The other is “what you pay if you move.”
Moving usually starts with a big one-time hit (movers, fees, deposits), but then you might save money each month
if the new rent is lower — or pay more if the new rent is higher.
This calculator estimates costs month-by-month, including optional annual rent increases and
a common incentive: free months (rent concessions). Then it finds the first month where the
cumulative cost of moving becomes less than or equal to the cumulative cost of staying. That month is your
break-even month.
Step 1: Define your two monthly rent paths
We start with two base rents:
Current rent (what you pay now) and New rent (what you’d pay after moving).
If you include rent increases, we apply them once per year. For example, a 5% annual increase means:
- Months 1–12: rent = base rent
- Months 13–24: rent = base rent × (1 + increase%)
- Months 25–36: rent = base rent × (1 + increase%)²
Step 2: Add one-time moving costs
Moving costs are treated as a one-time upfront amount. We separate them into:
one-time moving costs & fees (movers, truck, admin fees, utility setup)
and net deposit / upfront difference (extra cash tied up if the new deposit is larger than the refund
you expect from your current place).
In real life, deposits are often returned later, so “net deposit difference” is best interpreted as
cash you have to front during the move. If you expect a full refund and the deposits are equal,
you can set this to $0.
Step 3: Apply free months (if any)
If the new apartment offers 1–2 months free, the calculator subtracts those months of rent early in the moving scenario.
This is important because concessions typically make the move look cheaper at the beginning, which can significantly
shorten break-even.
Step 4: Compare cumulative totals and locate break-even
Each month, we compute:
- Cumulative cost if staying = sum of “stay rent” up to that month
- Cumulative cost if moving = one-time costs + sum of “new rent” up to that month (minus any free months)
Break-even happens at the earliest month m where:
CostMoving(m) ≤ CostStaying(m).
If that never happens within your chosen horizon, the calculator reports: “No break-even within the horizon.”
Quick intuition formula (simple case)
If you ignore rent increases and free months, a simple approximation is:
- Monthly savings = Current rent − New rent
- Total upfront = One-time costs + Net deposit difference
- Break-even months ≈ Total upfront ÷ Monthly savings
The calculator’s month-by-month method is more accurate because it can handle rent increases and concessions,
but the approximation is great for a quick sanity check.
🧪 Examples
Break-even examples (realistic scenarios)
Example A: Moving to save rent
Suppose your current rent is $2,200 and the new place is $1,950.
That’s a monthly savings of $250. If movers + fees cost $2,600
and you expect an extra $700 tied up in deposits, your upfront total is $3,300.
With the simple formula: break-even ≈ 3,300 ÷ 250 = 13.2 months.
The calculator will typically show a break-even around month 14 (because we count in whole months).
If you plan to stay 24 months, you’ll likely save money overall.
Example B: 1 month free changes everything
Using the same numbers as Example A, add 1 month free on the new lease.
That immediately reduces your moving scenario by roughly $1,950 (one month of new rent).
Now the upfront “hill” is much smaller — meaning your break-even could drop from ~14 months to something like
6–8 months, depending on the increase assumptions.
Example C: New rent is higher
If your new rent is $2,450 while your current rent is $2,200, you are paying
$250 more per month plus moving costs. Financially, the move does not “break even.”
The calculator will say something like: “No financial break-even — moving costs more than staying.”
That doesn’t mean the move is wrong. It means you’re paying for other benefits: a shorter commute,
a safer neighborhood, better roommates, a better gym, or peace of mind. This tool helps you quantify that tradeoff.
Example D: Rent increases tilt the answer
If your current rent tends to increase faster than your new rent (for example 7% vs 3% annually),
moving can break even sooner even if the initial rent difference is small. Over time, compounding rent increases
matter — especially if you plan to stay for 2–5 years.