What should count as a commute cost?
Include the costs that only happen because you travel to the workplace: train or bus fares, fuel, parking, tolls and any extra office-day spending you genuinely would not incur at home. Keeping those separate from normal household spending makes the comparison more useful.
Why annualise it?
A £15 daily fare can feel small, but three office days a week for 47 working weeks is £2,115 before parking, food or time. Annual numbers make job offers and hybrid-working policies much easier to compare.
Need to know what salary compensates for it?
The main Worth the Commute calculator works backwards from these costs and estimates the gross salary a new job needs to pay after UK tax, pensions and student loans.