Boots add variables generic charts ignore — stiff leather break-in, insulated liners, and work-sock bulk. Timberland and Dr Martens both have model-specific fit offsets; "size up for boots" is not universal.
Only when you need room for thick socks or an aftermarket insole — otherwise follow the brand's fit offset. Timberland and Dr Martens boots often run large in length, while UGG boots can feel smaller because of the lining. Measure in the socks you will wear.
Dr Martens boots usually run large in length but feel stiff because the leather upper takes time to break in. Many first-time buyers start by checking half a US size down, then judge pressure points separately from length. The 1460 and Jadon share similar boot logic; see model-level guides for width notes.