Do I really need 70% of my working income to retire comfortably?

The old line that you'll need about 70 per cent of your working income once you retire gets repeated so often it can start to feel like a law. This column pushes back on leaning too hard on any rule of thumb and makes the case for figuring out your own number instead. The reasoning starts from how you actually expect to live: which costs disappear when the commute and the mortgage do, which ones rise as travel or hobbies fill the calendar, and what your real spending looks like rather than a percentage someone picked for a headline. Building the estimate from the ground up tends to land closer to the truth than a tidy fraction of a paycheque. It's a helpful reframe for anyone trying to judge whether they've saved enough without overshooting or selling themselves short.