Use the same endpoints
Write the complete route for each option, from your starting address to the place you need to reach. Airport and station access can differ substantially. Include the departure journey, arrival transfer and any unavoidable wait that affects the day. Comparing only time aboard the vehicle misses much of the travel experience.
Specify the luggage and flexibility you need before collecting prices. A flight without the baggage you will bring is not equivalent to a train ticket that already accommodates it. Check the operator's current terms rather than assuming one mode always includes particular benefits.
Add the complete cash cost
Consider an invented flight costing $70, with $25 baggage and transfers of $18 and $22. The total is $135. A train ticket costs $110 with $8 and $5 local connections, totalling $123. Under these assumptions the train costs $12 less, although its headline ticket price is higher.
Add food only to the extent that one option changes what you would buy. If both require the same meal, charging it to only one side distorts the comparison. Include an overnight stay when a timetable genuinely makes it necessary, using a suitable actual quote.
Show time without forcing a price
List door to door time next to the cash total. Waiting, changes and arrival hours may matter differently from time spent seated. If the trip affects paid work or requires extra childcare, include those concrete costs. Otherwise you can assess comfort and time as preferences without assigning an invented hourly wage.
Before booking, inspect change and cancellation conditions for the exact fare. A cheap ticket that cannot accommodate a likely schedule change may be a poor fit. Keep both the chosen total and the assumptions used, especially luggage and transfer arrangements. This makes a later timetable or price change easier to evaluate without rebuilding the whole comparison from memory.
If travelling together, calculate the group total as well as the individual fare because shared transfers can alter the comparison.
