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CONVERSION TABLE FOR DERIVED SCORES

Adapted from Howard B. Lyman, Test Scores and What They Mean, Second Edition. Englewood Cliffs, N.J.: Prentice-Hall, Inc., 1971

z-Score (X-M)/s	T-Score (10z + 50)	Wechsler IQ (15z + 100)	Stanford-Binet IQ (16z + 100)	Scaled Score (3z + 10)	Percentile Rank
3.00	80	145	148	19	99.9
2.95	79.5	144	147	--	99.8
2.90	79	144	146	--	99.8
2.85	78.5	143	146	--	99.8
2.80	78	142	145	--	99.7
2.75	77.5	141	144	--	99.7
2.70	77	141	143	--	99.6
2.65	76.5	140	142	18	99.6
2.60	76	139	142	--	99.5
2.55	75.5	138	141	--	99.5
2.50	75	138	140	--	99.4
2.45	74.5	137	139	--	99.3
2.40	74	136	138	--	99.2
2.35	73.5	135	138	17	99.1
2.30	73	135	137	--	98.9
2.25	72.5	134	136	--	98.8
2.20	72	133	135	--	98.6
2.15	71.5	132	134	--	98.4
2.10	71	132	134	--	98.2
2.05	70.5	131	133	--	98.0
2.00	70	130	132	16	97.7
1.95	69.5	129	131	--	97.4
1.90	69	129	130	--	97.1
1.85	68.5	128	130	--	96.8
z-Score (X-M)/s	T-Score (10z + 50)	Wechsler IQ (15z + 100)	Stanford-Binet IQ (16z + 100)	Scaled Score (3z + 10)	Percentile Rank
1.80	68	127	129	--	96.4
1.75	67.5	126	128	--	96.0
1.70	67	126	127	--	95.5
1.65	66.5	125	126	15	95.0
1.60	66	124	126	--	94.5
1.55	65.5	123	125	--	93.9
1.50	65	123	124	--	93.3
1.45	64.5	122	123	--	92.6
1.40	64	121	122	--	91.9
1.35	63.5	120	122	14	91.2
1.30	63	120	121	--	90.3
1.25	62.5	119	120	--	89.4
1.20	62	118	119	--	88.5
1.15	61.5	117	118	--	87.5
1.10	61	117	118	--	86.4
1.05	60.5	116	117	--	85.3
1.00	60	115	116	13	84.1
0.95	59.5	114	115	--	82.9
0.90	59	114	114	--	81.6
0.85	58.5	113	114	--	80.2
0.80	58	112	113	--	78.8
0.75	57.5	111	112	--	77.3
0.70	57	111	112	--	75.8
0.65	56.5	110	110	12	74.2
z-Score (X-M)/s	T-Score (10z + 50)	Wechsler IQ (15z + 100)	Stanford-Binet IQ (16z + 100)	Scaled Score (3z + 10)	Percentile Rank
0.60	56	109	110	--	72.6
0.55	55.5	108	109	--	70.9
0.50	55	108	108	--	69.2
0.45	54.5	107	107	--	67.4
0.40	54	106	106	--	65.5
0.35	53.5	105	106	11	63.7
0.30	53	104	105	--	61.8
0.25	52.5	104	104	--	59.9
0.20	52	103	103	--	57.9
0.15	51.5	102	102	--	56.0
0.10	51	102	102	--	54.0
0.05	50.5	101	101	--	52.0
0.00	50	100	100	10	50.0
-0.05	49.5	99	99	--	48.0
-0.10	49	98	98	--	46.0
-0.15	48.5	98	98	--	44.0
-0.20	48	97	97	--	42.1
-0.25	47.5	96	96	--	40.1
-0.30	47	96	95	--	38.2
-0.35	46.5	95	94	9	36.3
-0.40	46	94	94	--	34.5
-0.45	45.5	93	93	--	32.6
-0.50	45	93	92	--	30.8
-0.55	44.5	92	91	--	29.1
z-Score (X-M)/s	T-Score (10z + 50)	Wechsler IQ (15z + 100)	Stanford-Binet IQ (16z + 100)	Scaled Score (3z + 10)	Percentile Rank
-0.60	44	91	90	--	27.4
-0.65	43.5	90	90	8	25.8
-0.70	43	90	89	--	24.2
-0.75	42.5	89	88	--	22.7
-0.80	42	88	87	--	21.2
-0.85	41.5	87	86	--	19.8
-0.90	41	87	86	--	18.4
-0.95	40.5	86	85	--	17.1
-1.00	40	85	84	7	15.9
-1.05	39.5	84	83	--	14.7
-1.10	39	84	82	--	13.6
-1.15	38.5	83	82	--	12.5
-1.20	38	82	81	--	11.5
-1.25	37.5	81	80	--	10.6
-1.30	37	81	79	--	9.7
-1.35	36.5	80	78	6	8.8
-1.40	36	79	78	--	8.1
-1.45	35.5	78	77	--	7.4
-1.50	35	78	76	--	6.7
-1.55	34.5	77	75	--	6.1
-1.60	34	76	74	--	5.5
-1.65	33.5	75	74	5	5.0
-1.70	33	75	73	--	4.5
-1.75	32.5	74	72	--	4.0
z-Score (X-M)/s	T-Score (10z + 50)	Wechsler IQ (15z + 100)	Stanford-Binet IQ (16z + 100)	Scaled Score (3z + 10)	Percentile Rank
-1.80	32	73	71	--	3.6
-1.85	31.5	72	70	--	3.2
-1.90	31	72	70	--	2.9
-1.95	30.5	71	69	--	2.6
-2.00	30	70	68	4	2.3
-2.05	29.5	69	67	--	2.0
-2.10	29	69	66	--	1.8
-2.15	28.5	68	66	--	1.6
-2.20	28	67	65	--	1.4
-2.25	27.5	66	64	--	1.2
-2.30	27	66	63	--	1.1
-2.35	26.5	65	62	3	0.9
-2.40	26	64	62	--	0.8
-2.45	25.5	63	61	--	0.7
-2.50	25	63	60	--	0.6
-2.55	24.5	62	59	--	0.5
-2.60	24	61	58	--	0.5
-2.65	23.5	60	58	2	0.4
-2.70	23	60	57	--	0.4
-2.75	22.5	59	56	--	0.3
-2.80	22	58	55	--	0.3
-2.85	21.5	57	54	--	0.2
-2.90	21	57	54	--	0.2
-2.95	20.5	56	53	--	0.2
-3.00	20	55	52	1	0.1

Association of Chief Psychologists with Ontario School Boards

CONVERSION TABLE FOR DERIVED SCORES

Adapted from Howard B. Lyman, Test Scores and What They Mean, Second Edition. Englewood Cliffs, N.J.: Prentice-Hall, Inc., 1971