IPC-2152

IPC-2152 - Determining Current-Carrying Capacity in Printed Board Design

Standard for Determining Current-Carrying Capacity in Printed Board Design

Maintained by Giorgi Gaprindashvili Published July 3, 2026 Updated September 18, 2026 Editorial check September 2026

Trace width, thickness and copper area

The trace width and copper thickness set its cross-sectional area. Actual temperature also depends on the surrounding board, connected copper and operating conditions.

Key facts

Full title: Standard for Determining Current-Carrying Capacity in Printed Board Design
Published by: IPC
Published: 2009; IPC currently lists the document as “No Longer Maintained”
Replaces: Provides dedicated current-capacity data beyond the legacy conductor-sizing relationship commonly associated with IPC-2221
Method: Empirical, based on testing of hundreds of board configurations
Accounts for: Copper weight, board thickness, plane proximity, laminate material and cooling environment (air or vacuum)
Result vs IPC-2221: Can differ in either direction because board construction and thermal context matter

What IPC-2152 is

IPC-2152 is a dedicated 2009 document for determining current-carrying capacity in printed boards. It was built from a broader test program than the historical trace-current relationship and provides charts and correction factors for board construction and thermal context.

IPC’s document revision table currently marks IPC-2152 as “No Longer Maintained”. That does not erase the published data, but it does mean the page should not describe IPC-2152 as an actively maintained current standard. For a production design, verify the method and requirements that your organization, customer or applicable design standard currently accepts.

How it improves on IPC-2221

The key advance is that IPC-2152 models the board around the trace. It applies correction factors for copper weight, board thickness, proximity to copper planes, laminate material and the cooling environment, none of which the IPC-2221 formula considers.

Because it captures heat spreading realistically, it often permits a narrower trace than IPC-2221 for the same current. Its testing also showed that on boards with good thermal spreading, internal traces can carry nearly as much current as external ones, overturning the old assumption that internal traces always need to be far wider.

How the standard is structured

The document has two parts: a main section with baseline conductor-sizing charts for boards tested in still air and in vacuum, and an appendix of correction factors for the real-world variables above.

Use the appropriate charts and documented corrections for the board under assessment. Check which of those a calculator implements: our trace tool uses one unadjusted published fit and reports its limits separately.

Caveats worth knowing

The baseline data assumes traces spaced more than about one inch apart. Closely spaced high-current traces heat one another, so their real temperature is higher than an isolated-trace result; tightly packed traces should be treated conservatively or analysed together.

As with any standard method, IPC-2152 is a design aid, not a guarantee. For critical or high-current designs, confirm the result with thermal simulation or prototype testing. The related guide walks through when IPC-2152 is worth the extra rigour versus a quick IPC-2221 estimate.

What IPC-2152 accounts for beyond IPC-2221

These variables can change the thermal result in either direction relative to a simple legacy estimate.
Factor	Effect on current-carrying capacity
Copper weight / thickness	More copper means more cross-section, so more current for a given width
Board thickness	Changes how heat spreads away from the trace
Plane proximity	Adjacent copper planes spread heat, allowing more current
Laminate material	Substrate thermal conductivity affects the temperature rise
Cooling environment	Baseline charts cover still air and vacuum; forced air improves it further

Tools that use this standard

PCB trace width calculator

Related standards

Standard	Relationship	What it means
IPC-2221	Compared with	IPC-2221C is the actively revised generic printed-board design standard; the familiar legacy trace-current relationship and IPC-2152 use different data/model assumptions.
IPC-2221C (2023)	Related current design reference	IPC-2221C is the actively revised generic printed-board design standard. IPC-2152 remains a separate 2009 current-capacity reference that IPC currently lists as No Longer Maintained.
MIL-STD-275 (IPC-D-275)	Supersedes basis of	The 1950s single-trace test data behind the old IPC-2221 charts, which IPC-2152's broader 2009 test program replaced.

Frequently asked questions

What is IPC-2152?

IPC-2152 is IPC’s 2009 “Standard for Determining Current-Carrying Capacity in Printed Board Design.” It is a test-based reference with board-construction corrections. IPC currently marks the document “No Longer Maintained,” so treat it as a published reference method rather than an actively maintained current standard.

What is the difference between IPC-2152 and IPC-2221?

IPC-2221 uses a single legacy formula from 1950s single-trace data; IPC-2152 is built on a broader test program covering many board configurations and adds correction factors for copper weight, board thickness, plane proximity and material. For the same current, the result can differ in either direction. The related guide compares them in detail.

Does IPC-2152 always give a narrower trace?

No. A baseline or corrected result may be wider or narrower than a legacy estimate. Evaluate the actual board construction and thermal conditions.

What does IPC-2152 account for that IPC-2221 does not?

Copper weight, board thickness, proximity to copper planes, laminate material and the cooling environment (its baseline charts cover still air and vacuum). IPC-2221's single formula ignores all of these.

Why do IPC-2152 calculators warn about trace spacing?

The standard's baseline data assumes traces spaced more than about one inch apart. Closely spaced high-current traces heat each other, so their real temperature is higher than an isolated-trace calculation predicts; treat tightly packed traces conservatively or analyse them together.

Should I use IPC-2152 or IPC-2221 for my design?

Use IPC-2152 data appropriate to the board construction for current-capacity decisions. A legacy formula can be a comparison, but should not be assumed to provide a safe upper bound.

Is IPC-2152 the current standard for trace current?

IPC-2152 remains an important published current-capacity reference, but IPC’s current revision table marks it “No Longer Maintained.” IPC-2221C is actively revised as the generic board-design standard. For a real design, use the current documents and methods required by your organization, customer or certification context rather than assuming IPC-2152 has active-maintenance status.

Source: IPC document revision table — IPC-2152 listed as No Longer Maintained. An overview for design reference - verify against the current edition before relying on it for compliance.