Abstract: Pattern data for at least two sizes are converted to knit data, regarding knitted products to be graded. Regarding the knit data for at least two sizes, characteristic points specifying shapes of the knitted products and intermediate shapes specifying shapes of the knitted products between the characteristic points are generated. By interpolating or extrapolating the characteristic points and the intermediate shapes, according to a desired size of the knitted products, characteristic points and intermediate shapes for the desired size are generated. Closed loops are generated by connecting the characteristic points and the intermediate shapes, and knit data for the desired size is generated by allocating knitted stitches within patterns specified by the closed loops. Without pattern data for intermediate sizes, knit data for the intermediate sizes are generated from the two size knit data.

Abstract: Pattern data for at least two sizes are converted to knit data, regarding knitted products to be graded. Regarding the knit data for at least two sizes, characteristic points specifying shapes of the knitted products and intermediate shapes specifying shapes of the knitted products between the characteristic points are generated. By interpolating or extrapolating the characteristic points and the intermediate shapes, according to a desired size of the knitted products, characteristic points and intermediate shapes for the desired size are generated. Closed loops are generated by connecting the characteristic points and the intermediate shapes, and knit data for the desired size is generated by allocating knitted stitches within patterns specified by the closed loops. Without pattern data for intermediate sizes, knit data for the intermediate sizes are generated from the two size knit data.

Abstract: Initial pattern data (50) and gauge data are stored, the pattern data is converted into knitting data based on the gauge data, and a knitted product is test-knitted. Sizes of the test-knitted product are compared with sizes indicated by the initial pattern data (50), and the pattern data or the knitting data is corrected. The correction amounts for the pattern data or for knitting data for two sizes are stored, and interpolation or extrapolation is performed based on the stored correction amounts to correct pattern data or knitting data for other sizes.

Abstract: Initial pattern data (50) and gauge data are stored, the pattern data is converted into knitting data based on the gauge data, and a knitted product is test-knitted. Sizes of the test-knitted product are compared with sizes indicated by the initial pattern data (50), and the pattern data or the knitting data is corrected. The correction amounts for the pattern data or for knitting data for two sizes are stored, and interpolation or extrapolation is performed based on the stored correction amounts to correct pattern data or knitting data for other sizes.