Couples don't relocate on one salary, but almost every cost-of-living comparison prices the move as if they did. Add the second income and the math changes in ways that aren't proportional: joint tax brackets bend, the destination's tax rates bite twice, and the household's investable surplus — the thing that actually compounds — can double or better. Sometimes that flips the verdict outright. Below, the same four routes priced solo and as a couple, with the partner earning 65% of the main salary and US couples filing jointly.
Four routes, solo vs couple
| Route | Solo verdict | Couple verdict | Swing |
|---|---|---|---|
| Chicago → Miami | −$7k | +$9k ← flips | +$16k |
| San Francisco → Austin | +$42k | +$87k | +$45k |
| Seattle → Austin | −$28k | −$33k | −$5k |
| London → Berlin | −$22k | −$67k | −$45k |
Why the second income isn't symmetric
The flip case works because of a mechanism specific to the US: married-filing-jointly brackets. MFJ brackets are roughly twice as wide as single brackets, so a second income that would be taxed at high single-filer marginal rates gets sheltered by the joint schedule — and the benefit lands differently in different cities, because state tax stacks on top. A move that was marginal solo can clear the bar once the joint math runs on both ends.
The reverse mechanism shows up abroad. Seattle to Austin gets worse with a partner: from $28k underwater to $33k underwater. The second income doesn't escape the destination's tax system — it's fully exposed to it. Moving a two-income household into a higher-tax country taxes the raise twice over, and no cost-of-living discount on rent fixes that.
And a route that's clearly won or lost stays that way. When both paths carry the same second income at similar tax treatment, the addition largely cancels — the verdict is still decided by the gap between the main offer and the destination's costs, as covered in the higher-salary guide.
The assumption you should argue with
One benchmark choice deserves to be challenged openly: household spending here does not double when the partner is added. That mirrors reality — rent, utilities, and much of daily life are shared — but it flatters the couple numbers, because most of the second income becomes investable surplus. If your household would genuinely scale its spending with income, the couple advantage shrinks accordingly. The simulator lets you set the household's actual monthly spend in both cities, plus a partner salary that changes after the move — the two knobs that matter most for a real couple's decision.
Common questions
How is a partner's income taxed in these numbers?
In the US with the married-with-kids setting, the couple's combined income runs through actual married-filing-jointly brackets — the same way a real return would be filed. Outside the US, each partner is taxed individually on their own salary, a disclosed approximation since joint-filing rules vary widely by country.
Why doesn't doubling income just double the verdict?
Three reasons: joint filing changes the marginal rate on the second income; the second income is taxed at the destination's rates too, so a high-tax destination penalizes both salaries; and the benchmark holds household spending fixed rather than doubling it, so the second income mostly converts to investable surplus — which compounds.
What does this assume about the partner's job after the move?
The benchmark assumes the partner finds an equivalent-paying job in the new city, which is the single most optimistic assumption in couple relocation. If the partner faces a pay cut, a licensing gap, or months without work, the picture worsens by exactly that amount — model it by setting a lower partner salary after the move in the simulator.
Methodology & sources
Computed by the MoveWorth simulation engine: progressive income tax (US federal + state + FICA brackets; PolicyEngine-derived UK curves; OECD-anchored effective rates elsewhere), cost-of-living-scaled spending, compounding raises and invested savings. Salary benchmarks: BLS OEWS metro medians for US cities (official), calibrated World Bank-derived estimates elsewhere (labeled). Rent: Census ACS. FX: dated ECB snapshot. Benchmark assumptions unless stated: mid-senior software-engineer offer, 25% savings rate, 3% raises, 7% annual return, 10-year horizon. This is a benchmark, not financial advice.
Couple figures set a partner salary of 65% of the main current salary, household "married + 2 kids," and assume the partner finds equivalent pay after the move. US: combined income through married-filing-jointly brackets. Elsewhere: each partner taxed individually as a single filer — an approximation, labeled in the app wherever it applies.