A salary abroad is only comparable once you know what it does not include

Two numbers that are not measuring the same thing

The first instinct on receiving an offer from abroad is to convert it and compare. That comparison is nearly meaningless, and not only because of the exchange rate. The two figures sit inside different systems that deduct different amounts and include different things by default.

What is bundled into employment varies enormously between countries: healthcare, pension contributions, sick pay, holiday, family leave, transport, sometimes housing. Where a system provides something as standard, the salary doesn’t need to cover it. Where it does not, the salary must.

So the question is never what the number is. It is what you are left with after deductions, and what you then have to buy that you previously received.

Work out what actually reaches you

Gross to net differs so much between countries that two identical gross salaries can leave the employee with materially different sums. Income tax, social contributions, mandatory insurances and local charges are all deducted in some places and not others, and the total burden falls very differently across income levels.

The reliable way to handle this is to ask the employer, in writing, for an illustrative net figure for your circumstances, and to treat it as an estimate rather than a promise. Then check the components against the official guidance for that country, because an employer’s illustration is prepared for a standard case and yours may not be one.

Anybody with a slightly complicated position — income from more than one country, a family situation the system treats specially, assets elsewhere — should get qualified advice before accepting rather than after, since some of these things are much easier to arrange at the start.

Then subtract what you now have to buy yourself

The second adjustment is the list of things the new arrangement does not include. Health cover, if the system requires it to be bought. A pension, if the employer contribution is smaller or absent. Transport, if you can no longer walk to work. Schooling, if the local option doesn’t suit and an alternative is expensive.

This is where offers that looked generous frequently stop looking generous, and where offers that looked modest sometimes improve considerably. The comparison only becomes honest when both sides are expressed as what remains after the necessities are covered.

Housing deserves its own line, since it is the largest item and the one most distorted by a foreigner’s starting position. Somebody without a local rental history or a guarantor often pays more, at least at first, than the local averages suggest.

The first year has costs the following ones do not

Any move carries a one-off burden that no salary comparison captures: deposits, furnishing, the fees of setting up, travel, a period of duplicated costs, and the gap before the first payment arrives. Where a relocation allowance exists, understand exactly what it covers and whether any of it must be repaid if you leave early.

That last condition is common enough to be worth reading carefully. A clawback tied to a minimum period converts a benefit into a commitment, and people occasionally discover it at the moment they most want to leave.

Set against that, some costs disappear. A car that is no longer needed, a mortgage that is now let out, memberships that lapse, a commute that stops being paid for. The honest calculation nets both sides rather than only counting the new expenses, and people considering a move tend to tally the additions carefully and the removals not at all.

What the number can’t capture

There are elements no arithmetic reaches. Whether the role advances a career or parks it. Whether the qualification you hold is recognised. What the working culture demands in hours. What happens to your position if the job ends, particularly where a permission depends on it.

People also underweight the currency question. Being paid in a currency you spend is simpler and safer than being paid in one you must convert, and where earnings and obligations are in different currencies the real value of a salary moves without anybody changing it.

The reasonable conclusion is that a job abroad is rarely a purely financial decision and should not be sold to yourself as one. Do the arithmetic properly so that the money is not the reason it goes wrong, and then make the decision on the other things, which is where it will actually be decided.