To illustrate the integrated effect of 10 measured soil and climatic parameters into a single number, a new index, that is, Relative Production Efficiency Index (RPEI), was developed for different agroclimatic zones of extreme northwest India regions representative of overall production efficiency of maize and wheat crops. Besides RPEI, the Relative Soil Quality Index (RSQI) was also developed. On relating the RSQI and RPEI, it was observed that temperate soils had the highest values of RSQI (85), but the RPEI value of this zone was lowest for both maize (71) and wheat (71) compared with two other agroclimatic zones. The highest value of RPEI was noted in the intermediate zone (RPEI, 78 for maize and 76 for wheat crop). The subtropical zone, which had the lowest RSQI value (65), had the lowest RSQI value (65) and had a comparatively higher RPEI compared with RSQI for both maize (73) and wheat (73) crops. Based on the RPEI, the intermediate zone was in cultivable class II followed by subtropical (cultivable class III) and temperate zone (cultivable class IV). The area sown under maize and wheat crops in all the three zones of extreme northwest India were also described by the RPEI. A positive and linear relationship between grain yield and RPEI was observed for both maize and wheat crops. The increase in grain yield with higher values of RPEI was greater for the wheat crop. The area under either maize or wheat crops increased by 2.04 and 2.3 thousand hectares during the last 5 years, respectively. This increase can be attributed to the higher values of relative production efficiency index in this zone. The RPEI developed could be used to project the suitability, in terms of production, of an area for growing maize and wheat crops and thus is useful for making land use decisions.