航位推算法（英语：Dead reckoning，简称 DR）是利用已知位置，结合移动速度跟方位，来推算出现有位置的过程。传统上的航海，现代则的惯性导航系统都应用航位推算法来找出位置。

航位推算法的缺点是，因为新的位置是用之前的位置推导出来，在过程中的误差值会被累加，因此它的错误率会随着时间而成长。

In navigation, dead reckoning or dead-reckoning (also ded for deduced reckoning or DR) is the process of calculating one's current position by using a previously determined position, or fix, and advancing that position based upon known or estimated speeds over elapsed time and course. The corresponding term in biology, used to describe the processes by which animals update their estimates of position or heading, is path integration.