Photometric observations of total solar eclipses allow one to determine the solar disc radius from the location of the inflection point of the solar limb brightness function. To do this, the eclipse light curve is described by integral equation of the brightness distribution function. The problem is solved through least squares fitting of the theoretical eclipse light curve to the observed one. For observations of the 11 August 1999 total solar eclipse, we derived an estimate for the solar radius equal to 959.66±0.03". This result can be refined by taking into account the lunar shape nonsphericity and by improving charts of the marginal zone of the Moon.