E-series of preferred numbers

This graph shows how almost any value between 1 and 10 is within ±10% of an E12 series value, and its difference from the ideal value in a geometric sequence

Two decades of E12 values, which would give resistor values of 1 Ω to 82 Ω

The E-series is a system of preferred numbers (also called preferred values) derived for use in electronic components. It consists of the E1, E3, E6, E12, E24, E48, E96 and E192 series, where the number after the 'E' designates the quantity of value "steps" in each series. Although it is theoretically possible to produce components of any value, in practice the need for inventory simplification has led the industry to settle on the E-series for resistors, capacitors, inductors, and zener diodes. Other types of electrical components are either specified by the Renard series (for example fuses) or are defined in relevant product standards (for example IEC 60228 for wires).

History

World War II military production was a major influence for establishing common standards across many industries. Later, Post–World War II baby boom and invention of the transistor kicked off demand for consumer electronics goods during the 1950s. As transistor radio production migrated towards Japan during the 1950s, it was critical for the electronic industry to have international standards.

In the early 20th century,^[1]^[2]^[3]^[4] resistor and capacitor value increments were much different than today.^[5] Over time, products evolved towards common values and eventually was documented to become an official standard, such as 1963 IEC Publication 63 (IEC 63),^[6] created by the International Electrotechnical Commission (IEC). Later IEC 63 was renamed, amended, revised into the current version known as IEC 60063:2015.^[7]

IEC 60063 release history:

1952 – 1st edition.^[8]
1963 – 2nd edition.^[6]
1967 – Amendment 1.^[6]
1977 – Amendment 2.^[6]
2015 – 3rd edition.^[7]

Overview

E-series preferred numbers were chosen such that when a component is manufactured that it will end up in a bin of roughly equally spaced values on a logarithmic scale. Each E-series subdivides the interval from 1 to 10 (decade) into steps of 1, 3, 6, 12, 24, 48, 96, 192. Subdivisions of E3 to E192 ensure the maximum error will be divided in the order of 40%, 20%, 10%, 5%, 2%, 1%, 0.5%. Also, the E192 series is used for 0.25% and 0.1% tolerance resistors.

Currently, the E-series is split into two major groupings: up to E24 is one group, and E48 and higher is the other group. The two main differences between each major group is the number of significant digits (2 digits for E3 to E24, 3 digits for E48 to E192) and different rounding rules. Since lower E-series up to E24 were defined and established long before the IEC standards were written, older series were not redefined when E48 to E192 series were created, otherwise it would have created problems in production and servicing of established products. It should be noted that some values in the E24 series don't exist in E48 to E192 series.

Example

The E3 series is defined as three numbers consisting of 1.00, 2.20, 4.70. If a manufacturer sold resistors with E3 series values in a range of 1 ohm to 10 megaohms, then the available resistance values (in ohm (Ω)) would be: 1, 2.2, 4.7, 10, 22, 47, 100, 220, 470, 1K, 2.2K, 4.7K, 10K, 22K, 47K, 100K, 220K, 470K, 1M, 2.2M, 4.7M, 10M.

Obsolete

The E1 series exists only for historical reasons. The E3 series is rarely used, except for some components with high variations like electrolytic capacitors, where the given tolerance is often unbalanced between negative and positive such as −30/+50% or −20/+80%, or for components with uncritical values such as pull-up resistors. The calculated tolerance for this series gives (³√10 − 1) ÷ (³√10 + 1) = 36.60%. While the standard only specifies a tolerance greater than 20%, other sources indicate 40% or 50%. Currently, most electrolytic capacitors are manufactured with values in the E6 or E12 series, thus E3 series is likely obsolete.

E24 vs E48, E96, E192

Since some values in the E24 series do not exist in the E48, E96 and E192 series, resistor manufacturers have added the missing E24 values to some of their 1%, 0.5%, 0.25%, 0.1% tolerance families. This allows easier purchasing migration between different tolerance parts. This type of combination is noted on resistor datasheets and webpages as "E96 + E24" and "E192 + E24".^[9]^[10]^[11]

Comparison of E24 vs E48 values:

matching – 1.00, 1.10, 7.50
missing – 1.20, 1.30, 1.50, 1.60, 1.80, 2.00, 2.20, 2.40, 2.70, 3.00, 3.30, 3.60, 3.90, 4.30, 4.70, 5.10, 5.60, 6.20, 6.80, 8.20, 9.10

Comparison of E24 vs E96 values:

matching – 1.00, 1.10, 1.30, 1.50, 2.00, 7.50
missing – 1.20, 1.60, 1.80, 2.20, 2.40, 2.70, 3.00, 3.30, 3.60, 3.90, 4.30, 4.70, 5.10, 5.60, 6.20, 6.80, 8.20, 9.10.

Comparison of E24 vs E192 values:

matching – 1.00, 1.10, 1.20, 1.30, 1.50, 1.60, 1.80, 2.00, 4.70, 7.50
missing – 2.20, 2.70, 3.00, 3.30, 3.60, 3.90, 4.30, 5.11, 5.60, 6.20, 6.80, 8.20, 9.10

Lists

A decade of the E12 values shown with their electronic color codes on resistors.

List of values for each E-series:

E1 value
- 1.00

E3 values (>20% tolerance)
- 1.00, 2.20, 4.70

E6 values (20% tolerance)
- 1.00, 1.50, 2.20, 3.30, 4.70, 6.80

E12 values (10% tolerance)
- 1.00, 1.20, 1.50, 1.80, 2.20, 2.70, 3.30, 3.90, 4.70, 5.60, 6.80, 8.20

E24 values (5% tolerance)
- 1.00, 1.10, 1.20, 1.30, 1.50, 1.60, 1.80, 2.00, 2.20, 2.40, 2.70, 3.00, 3.30, 3.60, 3.90, 4.30, 4.70, 5.10, 5.60, 6.20, 6.80, 7.50, 8.20, 9.10

E48 values (2% tolerance) - (see notes in previous section)
- 1.00, 1.05, 1.10, 1.15, 1.21, 1.27, 1.33, 1.40, 1.47, 1.54, 1.62, 1.69, 1.78, 1.87, 1.96, 2.05, 2.15, 2.26, 2.37, 2.49, 2.61, 2.74, 2.87, 3.01, 3.16, 3.32, 3.48, 3.65, 3.83, 4.02, 4.22, 4.42, 4.64, 4.87, 5.11, 5.36, 5.62, 5.90, 6.19, 6.49, 6.81, 7.15, 7.50, 7.87, 8.25, 8.66, 9.09, 9.53

E96 values (1% tolerance) - (see notes in previous section)
- 1.00, 1.02, 1.05, 1.07, 1.10, 1.13, 1.15, 1.18, 1.21, 1.24, 1.27, 1.30, 1.33, 1.37, 1.40, 1.43, 1.47, 1.50, 1.54, 1.58, 1.62, 1.65, 1.69, 1.74, 1.78, 1.82, 1.87, 1.91, 1.96, 2.00, 2.05, 2.10, 2.15, 2.21, 2.26, 2.32, 2.37, 2.43, 2.49, 2.55, 2.61, 2.67, 2.74, 2.80, 2.87, 2.94, 3.01, 3.09, 3.16, 3.24, 3.32, 3.40, 3.48, 3.57, 3.65, 3.74, 3.83, 3.92, 4.02, 4.12, 4.22, 4.32, 4.42, 4.53, 4.64, 4.75, 4.87, 4.99, 5.11, 5.23, 5.36, 5.49, 5.62, 5.76, 5.90, 6.04, 6.19, 6.34, 6.49, 6.65, 6.81, 6.98, 7.15, 7.32, 7.50, 7.68, 7.87, 8.06, 8.25, 8.45, 8.66, 8.87, 9.09, 9.31, 9.53, 9.76

E192 values (0.5% and lower tolerance) - (see notes in previous section)
- 1.00, 1.01, 1.02, 1.04, 1.05, 1.06, 1.07, 1.09, 1.10, 1.11, 1.13, 1.14, 1.15, 1.17, 1.18, 1.20, 1.21, 1.23, 1.24, 1.26, 1.27, 1.29, 1.30, 1.32, 1.33, 1.35, 1.37, 1.38, 1.40, 1.42, 1.43, 1.45, 1.47, 1.49, 1.50, 1.52, 1.54, 1.56, 1.58, 1.60, 1.62, 1.64, 1.65, 1.67, 1.69, 1.72, 1.74, 1.76, 1.78, 1.80, 1.82, 1.84, 1.87, 1.89, 1.91, 1.93, 1.96, 1.98, 2.00, 2.03, 2.05, 2.08, 2.10, 2.13, 2.15, 2.18, 2.21, 2.23, 2.26, 2.29, 2.32, 2.34, 2.37, 2.40, 2.43, 2.46, 2.49, 2.52, 2.55, 2.58, 2.61, 2.64, 2.67, 2.71, 2.74, 2.77, 2.80, 2.84, 2.87, 2.91, 2.94, 2.98, 3.01, 3.05, 3.09, 3.12, 3.16, 3.20, 3.24, 3.28, 3.32, 3.36, 3.40, 3.44, 3.48, 3.52, 3.57, 3.61, 3.65, 3.70, 3.74, 3.79, 3.83, 3.88, 3.92, 3.97, 4.02, 4.07, 4.12, 4.17, 4.22, 4.27, 4.32, 4.37, 4.42, 4.48, 4.53, 4.59, 4.64, 4.70, 4.75, 4.81, 4.87, 4.93, 4.99, 5.05, 5.11, 5.17, 5.23, 5.30, 5.36, 5.42, 5.49, 5.56, 5.62, 5.69, 5.76, 5.83, 5.90, 5.97, 6.04, 6.12, 6.19, 6.26, 6.34, 6.42, 6.49, 6.57, 6.65, 6.73, 6.81, 6.90, 6.98, 7.06, 7.15, 7.23, 7.32, 7.41, 7.50, 7.59, 7.68, 7.77, 7.87, 7.96, 8.06, 8.16, 8.25, 8.35, 8.45, 8.56, 8.66, 8.76, 8.87, 8.98, 9.09, 9.20, 9.31, 9.42, 9.53, 9.65, 9.76, 9.88

Table

E3	E6	E12	E24	E48	E96	E192
1.00	1.00	1.00	1.00	1.00	1.00	1.00
					1.00	1.01
					1.02	1.02
					1.02	1.04
				1.05	1.05	1.05
					1.05	1.06
					1.07	1.07
					1.07	1.09
			1.10	1.10	1.10	1.10
					1.10	1.11
					1.13	1.13
					1.13	1.14
				1.15	1.15	1.15
					1.15	1.17
					1.18	1.18
					1.18	1.20
		1.20	1.20	1.21	1.21	1.21
					1.21	1.23
					1.24	1.24
					1.24	1.26
				1.27	1.27	1.27
					1.27	1.29
					1.30	1.30
					1.30	1.32
			1.30	1.33	1.33	1.33
					1.33	1.35
					1.37	1.37
					1.37	1.38
				1.40	1.40	1.40
					1.40	1.42
					1.43	1.43
					1.43	1.45
	1.50	1.50	1.50	1.47	1.47	1.47
					1.47	1.49
					1.50	1.50
					1.50	1.52
				1.54	1.54	1.54
					1.54	1.56
					1.58	1.58
					1.58	1.60
			1.60	1.62	1.62	1.62
					1.62	1.64
					1.65	1.65
					1.65	1.67
				1.69	1.69	1.69
					1.69	1.72
					1.74	1.74
					1.74	1.76
		1.80	1.80	1.78	1.78	1.78
					1.78	1.80
					1.82	1.82
					1.82	1.84
				1.87	1.87	1.87
					1.87	1.89
					1.91	1.91
					1.91	1.93
			2.00	1.96	1.96	1.96
					1.96	1.98
					2.00	2.00
					2.00	2.03
				2.05	2.05	2.05
					2.05	2.08
					2.10	2.10
					2.10	2.13

E3	E6	E12	E24	E48	E96	E192
2.20	2.20	2.20	2.20	2.15	2.15	2.15
					2.15	2.18
					2.21	2.21
					2.21	2.23
				2.26	2.26	2.26
					2.26	2.29
					2.32	2.32
					2.32	2.34
			2.40	2.37	2.37	2.37
					2.37	2.40
					2.43	2.43
					2.43	2.46
				2.49	2.49	2.49
					2.49	2.52
					2.55	2.55
					2.55	2.58
		2.70	2.70	2.61	2.61	2.61
					2.61	2.64
					2.67	2.67
					2.67	2.71
				2.74	2.74	2.74
					2.74	2.77
					2.80	2.80
					2.80	2.84
			3.00	2.87	2.87	2.87
					2.87	2.91
					2.94	2.94
					2.94	2.98
				3.01	3.01	3.01
					3.01	3.05
					3.09	3.09
					3.09	3.12
	3.30	3.30	3.30	3.16	3.16	3.16
					3.16	3.20
					3.24	3.24
					3.24	3.28
				3.32	3.32	3.32
					3.32	3.36
					3.40	3.40
					3.40	3.44
			3.60	3.48	3.48	3.48
					3.48	3.52
					3.57	3.57
					3.57	3.61
				3.65	3.65	3.65
					3.65	3.70
					3.74	3.74
					3.74	3.79
		3.90	3.90	3.83	3.83	3.83
					3.83	3.88
					3.92	3.92
					3.92	3.97
				4.02	4.02	4.02
					4.02	4.07
					4.12	4.12
					4.12	4.17
			4.30	4.22	4.22	4.22
					4.22	4.27
					4.32	4.32
					4.32	4.37
				4.42	4.42	4.42
					4.42	4.48
					4.53	4.53
					4.53	4.59

E3	E6	E12	E24	E48	E96	E192
4.70	4.70	4.70	4.70	4.64	4.64	4.64
					4.64	4.70
					4.75	4.75
					4.75	4.81
				4.87	4.87	4.87
					4.87	4.93
					4.99	4.99
					4.99	5.05
			5.10	5.11	5.11	5.11
					5.11	5.17
					5.23	5.23
					5.23	5.30
				5.36	5.36	5.36
					5.36	5.42
					5.49	5.49
					5.49	5.56
		5.60	5.60	5.62	5.62	5.62
					5.62	5.69
					5.76	5.76
					5.76	5.83
				5.90	5.90	5.90
					5.90	5.97
					6.04	6.04
					6.04	6.12
			6.20	6.19	6.19	6.19
					6.19	6.26
					6.34	6.34
					6.34	6.42
				6.49	6.49	6.49
					6.49	6.57
					6.65	6.65
					6.65	6.73
	6.80	6.80	6.80	6.81	6.81	6.81
					6.81	6.90
					6.98	6.98
					6.98	7.06
				7.15	7.15	7.15
					7.15	7.23
					7.32	7.32
					7.32	7.41
			7.50	7.50	7.50	7.50
					7.50	7.59
					7.68	7.68
					7.68	7.77
				7.87	7.87	7.87
					7.87	7.96
					8.06	8.06
					8.06	8.16
		8.20	8.20	8.25	8.25	8.25
					8.25	8.35
					8.45	8.45
					8.45	8.56
				8.66	8.66	8.66
					8.66	8.76
					8.87	8.87
					8.87	8.98
			9.10	9.09	9.09	9.09
					9.09	9.20
					9.31	9.31
					9.31	9.42
				9.53	9.53	9.53
					9.53	9.65
					9.76	9.76
					9.76	9.88

References

↑ "1930 Catalog - Page 139 - Capacitors (Condensers)". Allied Radio. Archived from the original on 11 July 2017. Retrieved 11 July 2017.
↑ "1940 Catalog - Page 54 - Capacitors (Condensers)". RadioShack. Archived from the original on 11 July 2017. Retrieved 11 July 2017.
↑ "1930 Catalog - Page 141 - Resistors". Allied Radio. Archived from the original on 11 July 2017. Retrieved 11 July 2017.
↑ "1940 Catalog - Page 60 - Resistors". RadioShack. Archived from the original on 11 July 2017. Retrieved 11 July 2017.
↑ "2017 Catalog - Pages 29 to 41 - Passives" (PDF). Jameco Electronics. Archived from the original (PDF) on 11 July 2017. Retrieved 11 July 2017.
1 2 3 4 IEC 60063:1963 - Preferred number series for resistors and capacitors. International Electrotechnical Commission (IEC). 1963. Archived from the original on 11 July 2017. Retrieved 11 July 2017.
1 2 IEC 60063:2015 - Preferred number series for resistors and capacitors. International Electrotechnical Commission (IEC). 2015. Archived from the original on 11 July 2017. Retrieved 11 July 2017.
↑ IEC 60063:1952 - Series of preferred values and their associated tolerances for resistors and capacitors. International Electrotechnical Commission (IEC). 1952. Archived from the original on 11 July 2017. Retrieved 11 July 2017.
↑ "Standard Values Used in Capacitors, Inductors, and Resistors". Bourns. Archived from the original on 11 July 2017. Retrieved 11 July 2017.
↑ "D/CRCW e3 - Standard Thick Film Chip Resistors - Datasheet" (PDF). Vishay Intertechnology. Archived from the original (PDF) on 11 July 2017. Retrieved 11 July 2017.
↑ "TNPW e3 - High Stability Thin Film Flat Chip Resistors - Datasheet" (PDF). Vishay Intertechnology. Archived from the original (PDF) on 11 July 2017. Retrieved 11 July 2017.

External links

IEC 60063:2015 - Preferred number series for resistors and capacitors - IEC
Standard Series Values in a Decade for Resistances and Capacitances - Vishay
Calculate standard resistor values in Excel - EDN magazine

List of International Electrotechnical Commission standards
IEC standards	IEC 60027 IEC 60034 IEC 60038 IEC 60062 IEC 60063 IEC 60068 IEC 60112 IEC 60228 IEC 60269 IEC 60297 IEC 60309 IEC 60320 IEC 60364 IEC 60446 IEC 60559 IEC 60601 IEC 60870 IEC 60870-5 IEC 60870-6 IEC 60906-1 IEC 60908 IEC 60929 IEC 60958 AES3 S/PDIF IEC 61030 IEC 61131 IEC 61131-3 IEC 61158 IEC 61162 IEC 61334 IEC 61346 IEC 61355 IEC 61400 IEC 61499 IEC 61508 IEC 61511 IEC 61850 IEC 61883 IEC 61960 IEC 61968 IEC 61970 IEC 62014-4 IEC 62056 IEC 62061 IEC 62196 IEC 62262 IEC 62264 IEC 62304 IEC 62325 IEC 62351 IEC 62365 IEC 62366 IEC 62379 IEC 62386 IEC 62455 IEC 62680 IEC 62682 IEC 62700
ISO/IEC standards	ISO/IEC 646 ISO/IEC 2022 ISO/IEC 5218 ISO/IEC 6429 ISO/IEC 6523 ISO/IEC 7810 ISO/IEC 7811 ISO/IEC 7812 ISO/IEC 7813 ISO/IEC 7816 ISO/IEC 7942 ISO/IEC 8613 ISO/IEC 8632 ISO/IEC 8652 ISO/IEC 8859 ISO/IEC 9126 ISO/IEC 9293 ISO/IEC 9592 ISO/IEC 9593 ISO/IEC 9899 ISO/IEC 9945 ISO/IEC 9995 ISO/IEC 10021 ISO/IEC 10116 ISO/IEC 10165 ISO/IEC 10179 ISO/IEC 10646 ISO/IEC 10967 ISO/IEC 11172 ISO/IEC 11179 ISO/IEC 11404 ISO/IEC 11544 ISO/IEC 11801 ISO/IEC 12207 ISO/IEC 13250 ISO/IEC 13346 ISO/IEC 13522-5 ISO/IEC 13568 ISO/IEC 13818 ISO/IEC 14443 ISO/IEC 14496 ISO/IEC 14882 ISO/IEC 15288 ISO/IEC 15291 ISO/IEC 15408 ISO/IEC 15444 ISO/IEC 15445 ISO/IEC 15504 ISO/IEC 15511 ISO/IEC 15693 ISO/IEC 16262 ISO/IEC 17024 ISO/IEC 17025 ISO/IEC 18000 ISO/IEC 18004 ISO/IEC 18014 ISO/IEC 19752 ISO/IEC 19757 ISO/IEC 19770 ISO/IEC 19788 ISO/IEC 20000 ISO/IEC 21000 ISO/IEC 21827 ISO/IEC 23003 ISO/IEC 23270 ISO/IEC 23360 ISO/IEC 24707 ISO/IEC 24727 ISO/IEC 24744 ISO/IEC 26300 ISO/IEC 27000 ISO/IEC 27000-series ISO/IEC 27002 ISO/IEC 27040 ISO/IEC 29119 ISO/IEC 33001 ISO/IEC 42010 ISO/IEC 80000 ISO/IEC 38500 ISO/IEC 4909
Related	International Electrotechnical Commission

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