Work Out Whether Your Connection Is Actually Makeable
A connection that shows up in search results is only 'legal' by the airline's own minimum — which assumes you walk fast, your bags make it, and nobody is queueing at passport control. This prints the two numbers side by side: the minutes you have, and the minutes the transfer actually needs once you count the terminal change, the bag recheck, and immigration. Local only; nothing about your trip leaves the tab.
- Buffer
- Minutes held versus minutes required, computed in your tab
- local
- What it replaces
- Guessing that a legal connection is a safe one
- $0.00
- Input
- Two times plus four yes/no facts about the transfer
- no card
- Output
- A margin, a breakdown, and one next move
- recomputed
What you pay otherwise
| Route | What you get | Cost |
|---|---|---|
| Booking a separate ticket to be safe | An extra flight you may not need | $80–$300 |
| Airport overnight after a miss | Hotel, taxi, and a rebooking queue | $180+ |
| Trusting the search result | Legal minimum, not survivable minimum | a coin flip |
| This page | The margin in minutes, with the reasons | $0 |
The workflow
Enter arrival and departure in 24-hour time
Use the times on the ticket, not the ones you remember. If the departure is after midnight, add 24 to the hour — the tool reads 25:20 as 01:20 tomorrow, which keeps the arithmetic honest instead of returning a negative buffer.
Answer the four transfer questions honestly
Terminal change, checked bags, international-to-domestic, and airport size are what move the required buffer. A domestic same-terminal transfer at a small airport needs 45 minutes; add immigration and a bag recheck and the same walk needs two hours.
Read the margin, not the verdict
COMFORTABLE means the margin covers a delay; TIGHT means it covers only a clean run. The number beneath the stamp is the one to act on — a 12-minute margin is a missed flight wearing a green label.
Change one factor and re-run before you pay
Re-run with the later connecting flight to see what the margin becomes. Booking the version with 90 minutes instead of 40 is usually cheaper than the hotel night the tight one costs you.
Worked example
Sample: FCO arrival 14:05, departure 15:35 Minutes held 90 Base (domestic) 45 Terminal change +30 Bag recheck +25 Immigration +40 Required 140 Margin -50 → MISSED Uploaded nothing — computed in the tab
Numbers above are sample data produced by the tool's own pre-loaded example, run in the browser — not averages or measured benchmarks.
What breaks this
Entering 12-hour times without am/pm reads 1:35 as 01:35 and inverts the buffer — use 24-hour. Answering 'no terminal change' on a ticket that says otherwise is the most common way this returns a green result for a doomed transfer. Treating a COMFORTABLE margin as a guarantee over-reads it: the calculator scores the walk, not the inbound aircraft's punctuality.
Try it now
A 90-minute connection at a large airport with immigration is loaded, and it fails. Change the departure to 16:35 and watch the stub re-stamp.
Open the buffer planner →Go deeper: the printable chit
The buffer check is free forever. The $4 one-time tier adds:
- Printable chit — the connection on one pocket-sized slip — estimate: ~8 min saved versus re-checking the times at the gate.
- Saved trips shelf — keep up to 10 itineraries in this browser — estimate: ~10 min saved per multi-leg trip of re-entering times.
- Alternative comparison — two connecting flights side by side — estimate: ~12 min saved per booking decision.