SMD Sizes Chart: 0402, 0603, 0805, 1206 in mm and Inches

You order 0603 resistors, the reels arrive, and the parts are far too small for the pads. Nobody misread the drawing; one side meant inch-based 0603 and the other meant millimeter-based 0603. SMD sizes are written as four-digit codes for length and width. In the common imperial (EIA) system, an 0603 part is about 1.6 × 0.8 mm. In the metric system, “0603” means 0.6 × 0.3 mm, which is an imperial 0201. The chart below gives every common resistor and capacitor size in both codes, in millimeters and inches, with the power rating and thickness you can expect, followed by diode, transistor and LED packages.

1. SMD Size Chart: Resistor and Capacitor Codes in mm and Inches

These dimensions come from Panasonic’s ERJ thick-film chip resistor catalog (2025), and the capacitor thickness from TDK’s general-purpose MLCC catalog (2026). Inch values are the millimeter values converted.

Imperial (EIA)	Metric	Length × width (mm)	Length × width (in)	Resistor power*	Typical MLCC thickness (mm)
01005	0402	0.40 × 0.20	0.016 × 0.008	0.031 W	0.20
0201	0603	0.60 × 0.30	0.024 × 0.012	0.05 W	0.30
0402	1005	1.00 × 0.50	0.039 × 0.020	0.1 W	0.50
0603	1608	1.60 × 0.80	0.063 × 0.031	0.1 W	0.80
0805	2012	2.00 × 1.25	0.079 × 0.049	0.125 W	0.60 / 0.85 / 1.25
1206	3216	3.20 × 1.60	0.126 × 0.063	0.25 W	0.60 to 1.60
1210	3225	3.20 × 2.50	0.126 × 0.098	0.5 W	1.25 to 2.50
1812	4532	4.50 × 3.20	0.177 × 0.126	0.75 W	1.60 to 3.20
2010	5025	5.00 × 2.50	0.197 × 0.098	0.75 W	—
2512	6432	6.40 × 3.20	0.252 × 0.126	1 W	—

\*Rated power at 70°C for one resistor series in each size (Panasonic ERJ catalog). Other series, including anti-surge and high-power types, are rated differently. MLCC thickness depends on the capacitance and voltage of each part (TDK MLCC catalog); a dash means the catalog does not list that size.

2. How Do You Read an SMD Size Code?

The first two digits are the length and the last two are the width. In imperial codes the unit is hundredths of an inch, so 0805 is roughly 0.08 × 0.05 inches. In metric codes the unit is tenths of a millimeter, so 2012 is 2.0 × 1.2 mm.

• The codes are rounded names, not exact sizes. An 01005 part is 0.016 × 0.008 in, not exactly 0.010 × 0.005.
• Some codes appear in both systems with different meanings, such as 0402 and 0603. Imperial 0402 is 1.0 × 0.5 mm; metric 0402 is 0.4 × 0.2 mm.
• Catalogs differ: some list imperial codes, some metric, some both. Check which one a datasheet uses before you compare.

How do you avoid the 0603 mix-up?

Write both codes, or the millimeter size, on the BOM: “0603 (1608 metric)”. Better still, list the full manufacturer part number, which fixes the size without any doubt. When a supplier quotes a size, check whether its catalog uses imperial or metric codes before you approve it. If you are not sure your footprint library matches your BOM, send the files for a DFM check and we will flag imperial/metric mismatches before assembly.

3. How Much Power Can Each SMD Resistor Size Handle?

Roughly, power doubles every one or two sizes up, from 0.031 W for 01005 to 1 W for 2512 in a standard thick-film series. Those figures are rated at 70°C ambient; above that temperature the allowed power falls, as shown in each datasheet’s derating curve.

If the resistor dissipates…	Smallest standard size that fits*
Up to 0.05 W	0201
Up to 0.1 W	0402 or 0603
Up to 0.125 W	0805
Up to 0.25 W	1206
Up to 0.5 W	1210
Up to 1 W	2512

\*Based on the Panasonic ERJ series above. Leave margin: a part running at its full rating in a warm enclosure runs hot and drifts. Check the derating curve in your part’s datasheet.

4. What Are the Common SMD Capacitor Sizes?

Ceramic capacitors (MLCCs) use the same codes as resistors, from 01005 to 1812 and beyond. 0402 and 0603 cover most decoupling capacitors; larger values and higher voltages move up to 0805, 1206 and 1210. Unlike resistors, MLCC height varies within one size: a 1206 MLCC can be 0.60 mm or 1.60 mm thick depending on its value, which matters for low-profile designs and for stencil design.

What sizes are tantalum capacitors?

Tantalum chip capacitors use letter case codes. These are the dimensions in KEMET’s T489 datasheet (2026):

Case	EIA metric code	Length × width × height (mm)	Maximum height (mm)
A	3216-18	3.2 × 1.6 × 1.6	1.8
B	3528-21	3.5 × 2.8 × 1.9	2.1
C	6032-28	6.0 × 3.2 × 2.5	2.8
D	7343-31	7.3 × 4.3 × 2.8	3.1

The last two digits of the EIA code are a height class, so check the maximum height in the datasheet (KEMET T489) rather than reading it from the code.

5. What Size Are SMD Diode and Transistor Packages?

They use package names instead of size codes. The table gives body length, width and seated height, plus the total span including the leads, from Nexperia and Diodes Incorporated package drawings.

Package	Typical use	Body L × W (mm)	Height (mm)	Span with leads (mm)
SOD-323	Small-signal diode	1.6–1.8 × 1.15–1.35	0.8–1.1	2.3–2.7
SOD-123	Diode, Zener	2.55–2.80 × 1.5–1.7	1.0–1.3	3.45–3.75
SOT-23	Small transistor, MOSFET	2.8–3.0 × 1.2–1.4	0.9–1.1	2.1–2.5
SMA	Rectifier, TVS	4.00–4.60 × 2.29–2.92	1.96–2.40	4.80–5.59
SMB	Rectifier, TVS	4.06–4.57 × 3.30–3.94	2.00–2.50	5.00–5.59
SOT-223	Regulator, power transistor	6.3–6.7 × 3.3–3.7	1.5–1.8	6.7–7.3
SMC	High-current rectifier, TVS	6.60–7.11 × 5.59–6.22	2.00–2.50	7.75–8.13
DPAK (TO-252)	Power MOSFET, regulator	6.00–6.20 × 6.45–6.70	2.19–2.39	9.40–10.41

Sources: Nexperia SOT23, SOT223, SOD123 and SOD323 drawings; Diodes Inc. SMA, SMB, SMC and DPAK drawings. Each maker’s letters for the dimensions differ, so compare the drawing, not the letter.

The same transistor can change pin order when its package changes; our transistor pinout guide shows the TO-92 and SOT-23 versions side by side.

6. What Do LED Sizes Like 2835, 3528 and 5050 Mean?

They are the LED body size in tenths of a millimeter. A 2835 LED is about 2.8 × 3.5 mm, a 3528 is the same footprint turned 90 degrees (3.5 × 2.8 mm), and a 5050 is about 5.0 × 5.0 mm. Lumileds datasheets confirm these outlines: the LUXEON 2835 is 3.50 × 2.80 mm, and the LUXEON 5050 is 5.00 × 5.00 mm for the square version (Lumileds 2835, Lumileds 5050).

The name tells you the size only. Two “2835” LEDs from different makers can have different pad layouts, polarity marks, power and brightness, so draw the footprint from the exact part’s datasheet.

7. How Do You Find the Size of an SMD Part on a Board?

Measure the body length and width with calipers and match them to the chart. Measure the body, not the solder fillet, and allow for the tolerances in section 1.

1. Measure length (along the terminals) and width.
2. Find the nearest row in the size chart.
3. For resistors, read the marking code to get the value; capacitors are usually unmarked, so the value needs a meter or the BOM.
4. If the board has a reference designator (R12, C5), look it up in the BOM or assembly drawing, which gives the exact part number.

8. Which SMD Size Should You Choose?

Use the smallest size that meets your power, voltage and capacitance needs, the board area, and the way the board will be built and repaired. Smaller is not automatically better.

Situation	Usual choice	Why
General-purpose design, standard assembly	0402 or 0603	Easy to place and inspect; wide part choice
Space-limited consumer or wearable	0201, sometimes 01005	Saves area; needs tighter stencil and placement control
Prototypes that will be hand-reworked	0603 or 0805	Can be soldered with a fine iron
Power or high-voltage resistors	1206 to 2512	Higher power rating and spacing
Automotive	Follow the part maker’s automotive line	AEC-Q200 qualified parts; some makers exclude their smallest sizes

What changes for automotive designs?

Passive parts for automotive use are usually qualified to AEC-Q200 (Rev E, 2023), the Automotive Electronics Council’s stress test standard for passive components. There is no universal minimum size, but makers set their own limits: in Panasonic’s ERJ catalog, for example, the 01005 series and one 0201 series are excluded from AEC-Q200, while another 0201 series (ERJ1GJ) is recommended for new automotive designs. Check the automotive line of the exact series you plan to use.

How does size affect assembly and cost?

Smaller parts need finer stencils, tighter placement accuracy and closer inspection. Mixing very small and very large parts on one board makes the stencil harder to balance. If you want to see how your size choices affect cost, send us your BOM and Gerber files for a quote within 24 hours. See our SMT assembly and BGA assembly pages for what we build, and mixed assembly or through-hole assembly when the board also has through-hole parts.

How are footprints for these sizes named?

Many CAD libraries follow the IPC-7351 naming style, which spells out the pad shape and size in the name. In that style, a pad called “r200_100” is a rectangle 2.00 × 1.00 mm (PCB Libraries explanation). Naming footprints this way makes it obvious when a library uses the wrong size.

Conclusion

SMD size codes describe length and width: in imperial codes, 0603 is about 1.6 × 0.8 mm; in metric codes, 0603 is a much smaller 0.6 × 0.3 mm part. Use the chart to convert between them, check power ratings and MLCC thickness for each size, and write either both codes or the full part number on your BOM. We quote within 24 hours with no minimum order quantity, and our hardware startup and battery and EV customers use us from prototype to production. Send your BOM and Gerber files and contact us today.

FAQ

What are the standard sizes of SMD components? The most common resistor and capacitor sizes are 0402, 0603, 0805 and 1206 (imperial codes), with 0201 and 01005 for very compact boards and 1210 to 2512 for higher power. Transistors and diodes use package names such as SOT-23, SOD-123 and SMA.

Are SMT and SMD the same? No. SMD (surface-mount device) is the component; SMT (surface-mount technology) is the assembly process that places and solders it.

What is the size of an SMD 2835 LED? About 2.8 × 3.5 mm. The name gives the body size in tenths of a millimeter.

How do I find the size of an SMD resistor? Measure its length and width with calipers and match them to a size chart: 1.6 × 0.8 mm is an 0603 (imperial), and 2.0 × 1.25 mm is an 0805.

What are the common sizes of SMD capacitors? Ceramic capacitors are most often 0402, 0603 and 0805; tantalum capacitors use case sizes A to D, from 3.2 × 1.6 mm (A) to 7.3 × 4.3 mm (D).