How do Books That Grow levels compare to other leveling systems?

The Books That Grow leveling system adheres to the Common Core State Standard text complexity guidelines. The chart below shows how our levels approximately correlate to other common leveling systems.


Grade Common Core: Reading A-Z Fountas and Pinnell Reading Recovery Developmental Reading Assessment (DRA) Scholastic Guided Reading
Lexile ATOS Degrees of Reading Power Flesch-Kincaid Reading Maturity Source Rater
A K ------------ aa, A, B, CA, B, CA-3A-6A-D
B 1 ------------ D, E, F, G, H, I, JD, E, F, G, H, I4-16A-16A-I
C 2 420 - 820 2.75-5.14 42-54 1.98-5.34 3.53-6.13 0.05-2.48 K, L, M, N, O, PJ, K, L, M18-208-30E-N
D 3 420 - 820 2.75-5.14 42-54 1.98-5.34 3.53-6.13 0.05-2.48 Q, R, S, TN, O, P22-2416-40J-Q
E 4 740 - 1010 4.97-7.03 52-60 4.51-7.73 5.42-7.92 0.84-5.75 U, V, W Q, R, S2620-50M-T
F 5 740 - 1010 4.97-7.03 52-60 4.51-7.73 5.42-7.92 0.84-5.75 X, Y, ZT, U, V2840-60Q-W
G 6 925 - 1185 7.00-9.98 57-67 6.51.10.34 7.04-9.57 4.11-10.66 --W, X, Y3050-70T-Z
H 7 925 - 1185 7.00-9.98 57-67 6.51.10.34 7.04-9.57 4.11-10.66 --Y, Z3270-80--
I 8 925 - 1185 7.00-9.98 57-67 6.51.10.34 7.04-9.57 4.11-10.66 --Z34----
J 9 1050 - 1335 9.67-12.01 62-72 8.32-12.12 8.41-10.81 9.02-13.93 ----------
K 10 1050 - 1335 9.67-12.01 62-72 8.32-12.12 8.41-10.81 9.02-13.93 ----------
L 11 1185 - 1385 11.20-14.10 67-74 10.34-14.2 9.57-12.00 12.30-14.50 ----------
M 12 1185 - 1385 11.20-14.10 67-74 10.34-14.2 9.57-12.00 12.30-14.50 ----------