Experiments were conducted to determine the influence of the number of grains counted using the Jeffries planimetric procedure of ASTM E 112 with a single test circle compared to the number counted using rectangles as suggested by Saltykov. Both planimetric methods produced similar estimates of the ASTM grain size number when the counts per field placement were high. The Saltykov rectangle method is a viable test method and produced good data down to low count numbers. Bias was not observed at low counts, only data scatter. The intercept count method, using only a single test circle per field, yielded slightly higher estimates of the ASTM grain size number, but the difference was relatively insignificant.