  We present a new method to determine the distance to B-stars in eclipsing
binary systems. The method is completely empirical, and it is based on the
existence of a very tight linear relationship between the V-band ``zero
magnitude angular diameter'' and the Stroemgren colour index c1 for B-stars; we
have empirically calibrated this relationship using local single B-stars with
accurate angular diameters, and B-stars in eclipsing binaries with precise
radii and parallax determinations. By studying the differential behaviour of
this relationship as predicted by theoretical stellar evolution models, we find
that it is independent of the stellar metallicities for a range of [Fe/H]
values between the solar one and that of young stars in the Magellanic Clouds.
The method, which also provides the value of the reddening to the system, is
discussed in detail, together with a thorough estimate of the associated
errors. We conclude that accurate Stroemgren photometry obtainable with 1.5
m-class telescopes of the LMC eclipsing binaries HV 2274 and HV 982 will allow
to obtain an empirical LMC distance with an accuracy of the order of 0.13 mag.
