ABSTRACT This paper presents a simple mathematical formula for correcting radio-echo-sounding data from an ice sheet or glacier for the effects of varying refractive index. The method requires some knowledge of the variation of refractive index with depth. In rare cases this may be known from direct measurement, but it can be estimated from the density profile. If even this is unknown, we show that the corrections can be estimated to an accuracy of about 3% of the depth to bubble close-off (i.e. to about +/- 2m for dry-snow conditions), and that the size of the refraction correction for a glacier or ice sheet with a flat bed is typically 6-10m under these conditions.