Bicycle tyre conversion chart

The bicycle tyre conversion chart below is especially useful when looking for replacement tyre, as it gives you different markings for the same tyre size. For example, when you are looking for replacement tyre that has only 28 x 1 ⁵/₈ x 1 ³/₄ on the sidewall, you can find that it is the same tyre if marked also as 47-622, 700 x 45C, 700 x 47C or 28 x 1 ³/₄.

WARNING: In almost 100% cases, the tyre size fraction part and its decimal equivalent are NOT INTERCHANGEABLE!
E.g. 26 x 1 ¹/₂ and 26 x 1.5 is NOT the same. We welcome any tyre sizing questions at loading... .

 

Tyre Bead Dia	ETRTO	Imperial	British	French
93	47-93	7×1 3/4		200×47
94	47-94	8×2		200×47
	50-94			200×50
110	54-110	8 1/2 × 2 8 1/2 × 2 1/8
137	32-137	8×1 1/4
152	54-152	10×2
194	44-194	10×1 5/8
203	44-203		12 1/2×1.75
	47-203		12 1/2×1.75×2 1/4 12 1/2×1.90	320×47
	50-203	12×2	12×2.00	320×50
	54-203		12×1.95	320×50
	57-203	12 1/2×2 1/4 R		320×57
	62-203	12 1/2×2 1/4		320×57
222	44-222	11×1 3/4×1 5/8
	47-222	11×1 3/4
239	32-239	12×1 3/8×1 3/4		300×32A
	57-239	12 1/2×2 1/4		300×55A
248	32-248	12×1 1/4		300×32
251	57-251	14 1/2×2 1/4		350×55A
254	47-254		14×1.75 14×1.90
	50-254		14×2.00
279	40-279	14×1 1/2		350×38B
288	32-288	14×1 3/8×1 1/4		350×32A
	37-288	14×1 3/8 14×1 5/8×1 3/8		350×37A 350A Confort 350A Ballon 350A 1/2 Ballon
	40-288	14×1 1/2 NL 14×1 5/8	14×1.75	350×38A
	44-288	14×1 3/8×1 5/8	14×1.75	350A 350×42A
298	32-298	14×1 1/4		350A 350×32A
	37-298	14×1 3/8
305	40-305		16×1.50
	44-305		16×1.75 16×1.90
	47-305		16×1.75×2
	50-305		16×2.00
	54-305	16×2	16×1.95 16×2.00	400×50
	57-305		16×2.125
	62-305		16×2.125
317	47-317	16×1 3/4
330	40-330	16×1 1/2		400×38B
337	37-337	16×1 3/8 NL
340	28-340			400×30
	32-340	16×1 3/8×1 1/4		400A 400×32A
	37-340	16×1 3/8		400×35A 400A Confort 400A Ballon 400A 1/2 Ballon
	44-340	16×1 5/8 16×1 3/8×1 5/8		400×42A
349	25-349	16×1 Primo
	28-349	16×1 1/8		400×32
	32-349	16×1 1/2 NL		400×32A
	35-349		16×1.35
	37-349	16×1 3/8
355	28-355	18×11/8
	35-355		18×1.35
	40-355		18×1.50
	47-355		18×1.75×2
	50-355		18×2.00
357	32-357	17×1 1/4
369	32-369	17×1 1/4 (Moulton)
387	37-387	18×1 3/8 NL
	40-387	18×1 1/2
390	28-390	18×1 1/8		450A 450×28A
	32-390	18×1 3/8×1 1/4		450A 450×32A
	37-390	18×1 3/8		450×35A 450A Confort 450A Ballon 450A 1/2 Ballon
	57-390			450×55A
400	32-400	18×1 1/4		450×32
	37-400	18×1 3/8
	44-400	20×1 3/4
	54-400	20×2×1 3/4
406	28-406	20×1 1/8
	32-406		20×1.25
	35-406		20×1.35
	37-406	20×1 3/8
	40-406		20×1.50
	42-406		20×1.60
	44-406		20×1.75
	47-406		20×1.75 20×1.75×2 20×1.90
	54-406	20×2	20×2.125	500×50
	57-406		20×2.125
	60-406		20×2.35
419	47-419	20×1 3/4
428	44-428	20×1 5/8
	54-428		20×2.00
432	40-432	20×1 1/2
438	32-438	20×1 3/8 NL		500×32A NL
	37-438	20×1 3/8 NL		500A
	40-438	20×1 3/8×1 1/2		500×38A
440	28-440			500×28A
	32-440	20×1 3/8×1 1/4		500A 500×32A
	37-440	20×1 3/8		500×37A 500A Confort 500A Ballon
	40-440	20×1 1/2 NL		500×38A
451	25-451	20×1 Primo
	28-451	20×1 1/8
	32-451	20×1 1/4		500×32
	37-451	20×1 3/8
456	50-456		22×2.00
484	44-484	22×1 1/2 22×1 5/8×1 1/2
	47-484	23×2		550×50B
	54-483 (484)		23×2.25
489	25-489		22×1.00
	32-489	22×1 1/4 NL		550×32A NL
	37-489	22×1 3/8 22×1 3/8×1 1/4 NL
	40-489	22×1 3/8×1 1/2
	50-489		22×2.00
490	28-490			550×28A
	32-490	22×1 3/8×1 1/4		550×32A
	37-490	22×1 3/8		550A 550A Confort 550A Ballon
498	37-498	22×1 3/8×1 1/4
501	32-501	22×1 1/4		550×32
	37-501	22×1 3/8
	47-501	24×1 3/4 R
507	37-507		24×1.5
	40-507		24×1.5
	44-507		24×1.625 24×1.75
	47-507	24×2×1 3/4	24×1.75 24×1.85/1.90 24×1.75×2
	(49)50-507		24×1.85/1.90 24×2.00 24×2.125
	54-507		24×2.10
	57-507		24×2.00 24×2.125
	60-507		24×2.35
	62-507		24×2.40
508	32-508	22×1 1/4×1	24×1.50
520	25-520	24×1		600×25C
	28-520	24×1 1/8		600×28C
	47-520	24×1 3/4
	57-520		25×2.25
531	44-531	24×1 5/8×1 1/2
534	35-534	24×1 1/2		600×32B
	37-534	24×1 1/2×1 3/4		600×35B
	40-534	24×1 1/2		600×38B
	54-534	24×1 1/2×2		600×50B 600×50
540	25-540		24×1.00
	32-540	24×1 3/8 24×1 3/8×1 1/4
	37-540	24×1 3/8
	40-540	24×1 3/8×1 1/2
541	22-541
	28-541			600×28A
	32-541	24×1 3/8×1 1/4 NL 24×1 1/4×1 3/8		600×32A 600×32A NL
	37-541	24×1 3/8		600×35A 600A Confort 600A Ballon 600A 1/2 Ballon
	37-541	24×1 1/2×1 3/8		600×38A
547	32-547	24×1 1/4		600A
	37-547	24×13/8 (Schwinn S-5)
559	25-559		26×1.00
	28-559		26×1.10
	32-559		26×1.25
	35-559		26×1.35
	37-559	26×1 5/8×1 3/8	26×1.40
	40-559		26×1.50
	42-559		26×1.60
	44-559		26×1.625 26×1.50/1.75
	47-559		26×1.75 26×1.75×2 26×1.80 26×1.85/1.90
	50-559	26×2	26×1.90 26×1.95 26×1.90/2.00 26×2.00/2.10
	54-559	26×2	26×1.95 26×2.10 26×2.125 26×2.20
	57-559		26×2.125 26×2.20/2.25 26×2.30
	60-559		26×2.35 26×2.40
	62-559		26×2.40 26×2.50
565	37-565	25×1 3/8
571	(22)23-571	26× 7/8		650×(22)23C
	25-571	26×1 5/8×1	26×1.75×1	650×25C
	32-571	26×1 5/8×1 1/4	26×1.75×1 1/4	650×32C
	40-571	26×1 3/8×1 1/2 NL 26×1 5/8×1 1/2 26×1 1/2 CS		650×35C 650×38C
	47-571	26×1 3/4 (Schwinn S-7)		650×45C 650 CS Confort
	54-571	26×2×1 3/4		650×50C
584	28-584	26×1 1/8×1 1/2		650×28B
	32-584			650×32B
	35-584	26×1 3/8×1 1/2		650×35B
	37-584	26×1 1/2×1 3/8 26×1 3/8×1 1/2		650×35B
	40-584	26×1 5/8×1 1/2 26×1 1/2		650B Standard 650×38B
	44-584	26×1 5/8×1 1/2 26×1 1/2×1 5/8 26×1 1/4 – 1 1/2		650×42B 650B Confort 650B 1/2 Ballon
	47-584	26×1 1/2×1 3/4 26×1 1/2×2		650×45B
	57-584		27.5×2.25	650B
	60-584		27.5×2.35	650B
590	20-590			650×20A
	25-590	26×1 1/8×1 1/4		650×25A
	28-590	26×1 1/8 26×1 3/8×1 1/8		650×28A
	32-590	26×1 1/4 26×1 3/8×1 1/4 26×1 1/4×1 3/8		650×32A
	35-590	26×1 3/8		650×35A
	37-590	26×1 3/8	26×1.375	650A 650×35A
	40-590	26×1 3/8×1 1/2 26×1 1/2×1 3/8	26×1.50	650×38A
	42-590	26×1 3/8×1 5/8 26×1 5/8×1 3/8		650×40A
	44-590
597	32-597	26×1 1/4
	37-597	26×1 3/8 (Schwinn S-6)
609	37-609	27×1 3/8×1 1/2 27×1 1/2×1 3/8
	40-609	27×1 1/2
622	18-622	28× 3/4		700×18C
	19-622			700×19C
	20-622	28×1 5/8×1 3/4 28×3/4		700×20C
	22-622	28×7/8		700×22C
	23-622	28×1 28×7/8 28×1 5/8×1		700×23C
	25-622	28×11/16	28×1.00	700×25C
	28-622	28×1 5/8×1 1/8 28×1 5/8×1 1/4×1 1/8	28×1.10	700×28C 700C Carrera
	30-622		28×1.20	700×30C
	32-622	28×1 5/8×1 1/4 27×1 1/4 (pre-1930s)	28×1.25	700C Course 700×32C
	35-622	28×1 5/8×1 3/8	28×1.35	700×35C
	37-622	28×1 5/8×1 3/8	28×1.40	700×35C
	40-622	28×1 5/8×1 1/2	28×1.50	700C 700×38C
	42-622		28×1.60	700×40C
	44-622	28×1 5/8	28×1.625	700×42C
	47-622	28×1 3/4×1 1/4 28×1 5/8×1 3/4	28×1.75	700×45C 700×47C
	50-622	28×1 5/8×2	28×1.90	700×50C
	54-622		29×2.10
	57-622		29×2.25
	60-622		29×2.35
	62-622		29×2.40
630	20-630	27×3/4
	22-630	27×7/8	27×1
	25-630	27×1 1/8 27×1 1/16	27×1
	28-630	27×1 1/4 fifty 27×1 1/4 W/O 27×11/8 27×1 1/4
	32-630	27×1 1/4
	35-630	27×1 3/8
635	28-635	28×1 1/2×1 1/8		700×28B
	32-635	28×1 1/2×1 1/4		700×32B 700B Course
	37-635	28×1 1/2×1 3/8		700×35B
	40-635	28×1 1/2		700B 700×38B
	44-635	28×1 1/2×1 5/8		700×40B 700×42B
642	28-642	28×1 3/8×1 1/8		700×28A
	37-642	28×1 3/8		700×35A

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In France the metric system was adopted so metric tyre sizes were introduced. The tyres were really the same size of course, so a nominal conversion factor of 25mm = 1inch was used. The following conversion table can be useful to translate between the two systems.

Diameter		Actual Section		Nominal Section
(mm)	(in)	(mm)	(in)	(mm)	(in)
300	12	25	1	[none]	1 1/4
350	14	28 (Carrera)	1 1/8	A	1 3/8
400	16	32 (Course)	1 1/4	B	1 1/2
450	18	35 (Confort) 37 (Demi-Ballon)	1 3/8	C	1 5/8
500	20	38	1 1/2	D	1 3/4
550	22	42	1 5/8
575	23	45	1 3/4
600	24	50	2
650	26
700	28

 

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