How to Find a Tire That Properly Fits Your Vehicle

Tire Types

Tire Sizing

Before you can determine the replacement tire that best fits your lifestyle, you must first find the tire that properly fits your vehicle. Identifying the proper replacement tire size is more than merely measuring the radius. It considers factors such as aspect ratio, load index, speed rating, metric type and more.

By using our site, you can easily find what fits you. Click on the Find Your Tire navigation above and simply enter your vehicle information and follow our lead. We’ll show you the Ironman Tires that are right for your vehicle.*

If you prefer to do a little math to find your tire size, you can use the following calculations:

Example: Size 275/55R20

275 (mm) / 25.4 = 10.8 inches
10.8 x .55 = 5.94
(5.94 x 2) + 20 = 31.88 inches

Section Width / 25.4 = SWi (converts mm to inches)

SWi x Aspect Ratio = Section Height (SH)

(SH x 2) + Rim Diameter Outside Diameter

Load Index Table

LI	kg	LBS	LI	kg	LBS	LI	kg	LBS	LI	kg	LBS
0	45	99.2	70	335	738.5	140	2500	5511.5	210	19000	41887.1
1	46.2	101.9	71	345	760.6	141	2575	5676.8	211	19500	42989.4
2	47.5	104.7	72	355	782.6	142	2650	5842.2	212	20000	44091.7
3	48.7	107.4	73	365	804.7	143	2725	6007.5	213	20600	45414.5
4	50	110.2	74	375	826.7	144	2800	6172.8	214	21200	46737.2
5	51.5	113.5	75	387	853.2	145	2900	6393.3	215	21800	48060.0
6	53	116.8	76	400	881.8	146	3000	6613.8	216	22400	49382.7
7	54.5	120.1	77	412	908.3	147	3075	6779.1	217	23000	50705.5
8	56	123.5	78	425	936.9	148	3150	6944.4	218	23600	52028.2
9	58	127.9	79	437	963.4	149	3250	7164.9	219	24300	53571.4
10	60	132.3	80	450	992.1	150	3350	7385.4	220	25000	55114.6
11	51.5	113.5	81	462	1018.5	151	3450	7605.8	221	25750	56768.1
12	63	138.9	82	475	1047.2	152	3550	7826.3	222	26500	58421.5
13	65	143.3	83	487	1073.6	153	3650	8046.7	223	27250	60075.0
14	67	147.7	84	500	1102.3	154	3750	8267.2	224	28000	61728.4
15	69	152.1	85	515	1135.4	155	3875	8542.8	225	29000	63933.0
16	71	156.5	86	530	1168.4	156	4000	8818.3	226	30000	66137.6
17	73	160.9	87	545	1201.5	157	4125	9093.9	227	30750	67791.0
18	75	165.3	88	560	1234.6	158	4250	9369.5	228	31500	69444.4
19	77.5	170.9	89	580	1278.7	159	4375	9645.1	229	32500	71649.0
20	80	176.4	90	600	1322.8	160	4500	9920.6	230	33500	73853.6
21	82.5	181.9	91	615	1355.8	161	4625	10196.2	231	34500	76058.2
22	85	187.4	92	630	1388.9	162	4750	10471.8	232	35500	78262.8
23	87.5	192.9	93	650	1433.0	163	4875	10747.4	233	36500	80467.4
24	90	198.4	94	670	1477.1	164	5000	11022.9	234	37500	82672.0
25	92.5	203.9	95	690	1521.2	165	5150	11353.6	235	38750	85427.7
26	95	209.4	96	710	1565.3	166	5300	11684.3	236	40000	88183.4
27	97.5	214.9	97	730	1609.3	167	5450	12015.0	237	41250	90939.2
28	100	220.5	98	750	1653.4	168	5600	12345.7	238	42500	93694.9
29	103	227.1	99	775	1708.6	169	5800	12786.6	239	43750	96450.6
30	106	233.7	100	800	1763.7	170	6000	13227.5	240	45000	99206.3
31	109	240.3	101	825	1818.8	171	6150	13558.2	241	46250	101962.1
32	112	246.9	102	850	1873.9	172	6300	13888.9	242	47500	104717.8
33	115	253.5	103	875	1929.0	173	6500	14329.8	243	48750	107473.5
34	118	260.1	104	900	1984.1	174	6700	14770.7	244	50000	110229.3
35	121	266.8	105	925	2039.2	175	6900	15211.6	245	51500	113536.2
36	125	275.6	106	950	2094.4	176	7100	15652.6	246	53000	116843.0
37	128	282.2	107	975	2149.5	177	7300	16093.5	247	54500	120149.9
38	132	291.0	108	1000	2204.6	178	7500	16534.4	248	56000	123456.8
39	136	299.8	109	1030	2270.7	179	7750	17085.5	249	58000	127866.0
40	140	308.6	110	1060	2336.9	180	8000	17636.7	250	60000	132275.1
41	145	319.7	111	1090	2403.0	181	8250	18187.8	251	61500	135582.0
42	150	330.7	112	1120	2469.1	182	8500	18739.0	252	63000	138888.9
43	155	341.7	113	1150	2535.3	183	8750	19290.1	253	65000	143298.1
44	160	352.7	114	1180	2601.4	184	9000	19841.3	254	67000	147707.2
45	165	363.8	115	1215	2678.6	185	9250	20392.4	255	69000	152116.4
160	170	374.8	116	1250	2755.7	186	9500	20943.6	256	71000	156525.6
47	175	385.8	117	1285	2832.9	187	9750	21494.7	257	73000	160934.7
48	180	396.8	118	1320	2910.1	188	10000	22045.9	258	75000	165343.9
49	185	407.8	119	1360	2998.2	189	10300	22707.2	259	77500	170855.4
50	190	418.9	120	1400	3086.4	190	10600	23368.6	260	80000	176366.8
51	195	429.9	121	1450	3196.6	191	10900	24030.0	261	82500	181878.3
52	200	440.9	122	1500	3306.9	192	11200	24691.4	262	85000	187389.8
53	206	454.1	123	1550	3417.1	193	11500	25352.7	263	87500	192901.2
54	212	467.4	124	1600	3527.3	194	11800	26014.1	264	90000	198412.7
55	218	480.6	125	1650	3637.6	195	12150	26785.7	265	92500	203924.2
56	224	493.8	126	1700	3747.8	196	12500	27557.3	266	95000	209435.6
57	230	507.1	127	1750	3858.0	197	12850	28328.9	267	97500	215947.1
58	236	520.3	128	1800	3968.3	198	13200	29100.5	268	10000	220458.6
59	243	535.7	129	1850	4078.5	199	13600	29982.4	269	103000	227072.3
60	250	551.1	130	1900	4188.7	200	14000	30864.2	270	106000	233686.1
61	257	566.6	131	1950	4298.9	201	14500	31966.5	271	109000	240299.8
62	265	584.2	132	2000	4409.2	202	15000	33068.8	272	112000	246913.6
63	272	599.6	133	2060	4541.4	203	15500	34171.1	273	115000	253527.3
64	280	617.3	134	2120	4673.7	204	16000	35273.4	274	118000	260141.1
65	290	639.3	135	2180	4806.0	205	16500	36375.7	275	121000	266754.9
66	300	661.4	136	2240	4938.3	206	17000	37478.0	276	125000	275573.2
67	307	676.8	137	2300	5070.5	207	17500	38580.2	277	128500	283289.2
68	315	694.4	138	2360	5202.8	208	18000	39682.5	278	132000	291005.3
69	325	716.5	139	2430	5357.1	209	18500	40784.8	279	136000	299823.6

Tire Speed Ratings Symbols

SPEED SYMBOL	MAXIMUM SPEED (km/h)	SPEED SYMBOL	MAXIMUM SPEED(km/h)
A1	5	K	110
A2	10	L	120
A3	15	M	130
A4	20	N	140
A5	25	P	150
A6	30	Q	160
A7	35	R	170
A8	40	S	180
B	50	T	190
C	60	U	200
D	65	H	210
E	70	V	240
F	80	W	270
G	90	Y	300
J	100	ZR	OVER 240

*Fitment Guide Terms of Use: This tire sizing tool, the website and all contents thereof and all services are provided on an "as is" basis without any warranty or condition, express, implied or statutory. We specifically disclaim any implied warranties of title, merchantability, fitness for a particular purpose and non-infringement. We do not warrant or guarantee that the contents of the website or the information provided by the tire sizing tools will be accurate, up-to-date or otherwise reliable.

In no event shall we be liable for lost profits or any special, incidental, indirect, consequential or reliance damages arising out of or in connection with this sizing tool or our services, under any legal theory, even if we have been advised of the possibility of such damages and notwithstanding the failure of essential purposes of any limited remedy.

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