Question 1

How do you use the Combined Values Chart?

Accepted Answer

Combine the two largest ratings first, round the result, then combine that result with the next largest, rounding again — repeating until one value remains. The formula behind every cell of the chart is a + b − (a × b) ÷ 100. For example, 20 combined with 20 is 36, not 40.

Question 2

Why are disability ratings combined instead of added?

Accepted Answer

Each rating is a percentage of the whole person, so a second impairment can only affect what remains after the first. Combining keeps any number of impairments from exceeding 100% of the person — adding them would overshoot the real rating every time.

Question 3

Does the order of combining matter?

Accepted Answer

Yes, in practice. The formula itself is symmetric, but the schedule rounds after each step, so folding three or more values in a different order can land one point off. The PDRS prescribes largest-first, and that order is the legal answer.

+	5	10	15	20	25	30	35	40	45	50
5	10	15	19	24	29	34	38	43	48	53
10	15	19	24	28	33	37	42	46	51	55
15	19	24	28	32	36	41	45	49	53	58
20	24	28	32	36	40	44	48	52	56	60
25	29	33	36	40	44	48	51	55	59	63
30	34	37	41	44	48	51	55	58	62	65
35	38	42	45	48	51	55	58	61	64	68
40	43	46	49	52	55	58	61	64	67	70
45	48	51	53	56	59	62	64	67	70	73
50	53	55	58	60	63	65	68	70	73	75
55	57	60	62	64	66	69	71	73	75	78
60	62	64	66	68	70	72	74	76	78	80
65	67	69	70	72	74	76	77	79	81	83
70	72	73	75	76	78	79	81	82	84	85
75	76	78	79	80	81	83	84	85	86	88
80	81	82	83	84	85	86	87	88	89	90
85	86	87	87	88	89	90	90	91	92	93
90	91	91	92	92	93	93	94	94	95	95
95	95	96	96	96	96	97	97	97	97	98

Combined Values Chart calculator

The chart

+	5	10	15	20	25	30	35	40	45	50
5	10	15	19	24	29	34	38	43	48	53
10	15	19	24	28	33	37	42	46	51	55
15	19	24	28	32	36	41	45	49	53	58
20	24	28	32	36	40	44	48	52	56	60
25	29	33	36	40	44	48	51	55	59	63
30	34	37	41	44	48	51	55	58	62	65
35	38	42	45	48	51	55	58	61	64	68
40	43	46	49	52	55	58	61	64	67	70
45	48	51	53	56	59	62	64	67	70	73
50	53	55	58	60	63	65	68	70	73	75
55	57	60	62	64	66	69	71	73	75	78
60	62	64	66	68	70	72	74	76	78	80
65	67	69	70	72	74	76	77	79	81	83
70	72	73	75	76	78	79	81	82	84	85
75	76	78	79	80	81	83	84	85	86	88
80	81	82	83	84	85	86	87	88	89	90
85	86	87	87	88	89	90	90	91	92	93
90	91	91	92	92	93	93	94	94	95	95
95	95	96	96	96	96	97	97	97	97	98

+	5	10	15	20	25	30	35	40	45	50
5	10	15	19	24	29	34	38	43	48	53
10	15	19	24	28	33	37	42	46	51	55
15	19	24	28	32	36	41	45	49	53	58
20	24	28	32	36	40	44	48	52	56	60
25	29	33	36	40	44	48	51	55	59	63
30	34	37	41	44	48	51	55	58	62	65
35	38	42	45	48	51	55	58	61	64	68
40	43	46	49	52	55	58	61	64	67	70
45	48	51	53	56	59	62	64	67	70	73
50	53	55	58	60	63	65	68	70	73	75
55	57	60	62	64	66	69	71	73	75	78
60	62	64	66	68	70	72	74	76	78	80
65	67	69	70	72	74	76	77	79	81	83
70	72	73	75	76	78	79	81	82	84	85
75	76	78	79	80	81	83	84	85	86	88
80	81	82	83	84	85	86	87	88	89	90
85	86	87	87	88	89	90	90	91	92	93
90	91	91	92	92	93	93	94	94	95	95
95	95	96	96	96	96	97	97	97	97	98

+	5	10	15	20	25	30	35	40	45	50
5	10	15	19	24	29	34	38	43	48	53
10	15	19	24	28	33	37	42	46	51	55
15	19	24	28	32	36	41	45	49	53	58
20	24	28	32	36	40	44	48	52	56	60
25	29	33	36	40	44	48	51	55	59	63
30	34	37	41	44	48	51	55	58	62	65
35	38	42	45	48	51	55	58	61	64	68
40	43	46	49	52	55	58	61	64	67	70
45	48	51	53	56	59	62	64	67	70	73
50	53	55	58	60	63	65	68	70	73	75
55	57	60	62	64	66	69	71	73	75	78
60	62	64	66	68	70	72	74	76	78	80
65	67	69	70	72	74	76	77	79	81	83
70	72	73	75	76	78	79	81	82	84	85
75	76	78	79	80	81	83	84	85	86	88
80	81	82	83	84	85	86	87	88	89	90
85	86	87	87	88	89	90	90	91	92	93
90	91	91	92	92	93	93	94	94	95	95
95	95	96	96	96	96	97	97	97	97	98