What Size Second Flag for a Flagpole? (Quick Answer)
The short answer: your second flag should be one standard size smaller than your U.S. flag, and it must never be larger than the U.S. flag. If you already fly a 3x5 U.S. flag, your state or military flag should be 2x3. If you fly a 4x6 U.S. flag, the second flag should be 3x5. That covers the vast majority of residential poles.
Use the table below to confirm your specific setup, then scroll to the hardware section to see exactly what you need to attach the second flag to your pole.
Secondary Flag Size Chart by Pole Height
This chart is based on the standard sizing rule that a flag's horizontal length (fly) should equal roughly one-quarter to one-third of the pole's total height. All major sizing guides align on the pairings below for typical U.S. wind conditions.
| Pole Height | U.S. Flag (Primary) | Second Flag (Secondary) | Combined Sq Ft |
|---|---|---|---|
| 20 ft | 3x5 (15 sq ft) | 2x3 (6 sq ft) | 21 sq ft |
| 25 ft | 4x6 (24 sq ft) | 3x5 (15 sq ft) | 39 sq ft |
| 30–35 ft | 5x8 (40 sq ft) | 4x6 (24 sq ft) | 64 sq ft |
| 40–45 ft | 6x10 (60 sq ft) | 5x8 (40 sq ft) | 100 sq ft |
| 50–55 ft | 8x12 (96 sq ft) | 6x10 (60 sq ft) | 156 sq ft |
Note: These are standard residential pairings for typical wind exposure. High-wind coastal or hilltop sites should size down one step on the secondary flag. Always confirm your specific pole's wind load rating with the manufacturer before adding a second flag.
How Do You Calculate Safe Combined Flag Area?
One size smaller is the practical rule of thumb. The engineering reason behind it: the total square footage of both flags combined should not exceed the square footage of the single largest flag your pole is rated to fly. For example, if your pole's maximum single-flag size is 5x8 (40 sq ft), the two flags together should stay at or below 40 sq ft. A 4x6 (24 sq ft) paired with a 3x5 (15 sq ft) totals 39 sq ft and fits safely within that limit.
Wind load does not increase in a straight line as flag area grows, it increases exponentially. Two flags that together exceed your pole's rated capacity can permanently bend an aluminum pole or snap a fiberglass one during a gust, and will wear out your halyard rope and snap hooks far faster than properly sized flags would.
Does the Second Flag Have to Be Smaller, or Can It Match the U.S. Flag?
This is the genuine disagreement in the industry. Most sources, including Liberty Flags and the Flagpole Store, recommend going one size smaller for the secondary flag. A minority position holds that two flags of equal size are acceptable as long as the U.S. flag remains on top. Here is how to decide:
- Go one size smaller if your pole is 25 ft or shorter, if you are in a high-wind area, or if your pole's manufacturer specifies a maximum wind-load rating. This is the safest, most widely recommended approach and the one FlagStars recommends.
- Matched sizes can work on taller commercial poles (30 ft and up) with a heavy-duty aluminum or steel shaft, provided the combined area still falls within the pole's rated capacity. If you go this route, consult your pole's documentation first.
The one hard rule from the U.S. Flag Code: the secondary flag must never be larger than the U.S. flag. Position also matters, the U.S. flag must always fly at the top of the pole, above the second flag.
Which Second Flag Should You Buy, and What Size?
The right second flag depends on what you want to display. Here are the three most common options, with the correct size logic for each:
State Flag
State flags are the most popular secondary choice. Because standard state flags are sold in 2x3, 3x5, and 4x6 sizes, you will almost always find the right size to pair with your U.S. flag. Browse the State Flags collection and match the size one step below your current U.S. flag. If your U.S. flag is 3x5, order a 2x3 state flag. If your U.S. flag is 4x6, order a 3x5 state flag.
Military Branch Flag
Army, Navy, Marine Corps, Air Force, Space Force, and Coast Guard flags are widely flown below the U.S. flag as a show of service pride or to honor a veteran in the household. The same one-size-smaller rule applies. The Military Flags collection carries branch flags in standard outdoor sizes. For precedence rules when flying multiple service flags together, see the related guide on the order of U.S. military service flags.
POW/MIA Flag
By federal law (10 U.S.C. § 903), the POW/MIA flag is authorized to fly directly below the U.S. flag at many federal buildings and veterans' facilities. For residential display, the same sizing principle applies: the POW/MIA flag should be equal to or smaller than the U.S. flag. The standard 3x5 POW/MIA flag pairs correctly below a 3x5 or 4x6 U.S. flag on a 20–25 ft pole. For more on proper POW/MIA display, see the full guide on the POW/MIA flag and how to display it.
Comparison: Which Second Flag Pairs With Which U.S. Flag Size?
| Your U.S. Flag Size | State Flag to Buy | Military/POW Flag to Buy | Correct? (Flag Code) |
|---|---|---|---|
| 2x3 | Not recommended (too small to pair) | Not recommended | N/A |
| 3x5 | 2x3 | 2x3 | Yes |
| 4x6 | 3x5 | 3x5 | Yes |
| 5x8 | 4x6 | 4x6 | Yes |
| 6x10 | 5x8 | 5x8 | Yes |
| 3x5 (U.S.) + 4x6 (state) | , | , | No, secondary is larger than U.S. flag |
What Hardware Do You Need to Fly a Second Flag?
Choosing the right second flag size is only half the job. Adding a second flag requires additional hardware, and what you need depends on your pole type.
External-Halyard Poles (Rope and Cleat)
This is the most common residential setup. The rope runs up the outside of the pole, over a pulley at the top, and ties off to a cleat near the base. To add a second flag, you need a second set of snap hooks attached to the same rope below the first set. The Nylon Bearing Rings and Aluminum Alloy Bearing Rings provide 360-degree rotation so each flag can spin independently, preventing the tangling that kills flags quickly. Space the two flag sets so the bottom edge of the upper flag clears the top edge of the lower flag by at least 12–24 inches when raised.
Internal-Cable Halyard Poles (Winch-Style)
These poles run a stainless steel cable internally. You cannot clip a snap hook directly to a steel cable, so each flag requires a flag arranger, a short length of cable the same height as the flag, with a quick link at each end. When flying two flags, you need two flag arrangers chained together in sequence, with the U.S. flag arranger on top. The Aluminium Alloy Spinning Rings pair with the snap hooks on each arranger to keep both flags rotating freely without twisting together.
Telescoping Poles
Telescoping poles vary significantly by brand and model. Some include built-in dual-flag hardware; others need manufacturer-specific parts. If your telescoping pole did not come with a second-flag kit, contact the manufacturer before purchasing add-on hardware, as generic snap hooks may not fit the internal sections correctly. The ABS Plastic Spinning Rings work with standard snap-hook setups on many telescoping models and are a good starting point for lighter 2x3 or 3x5 secondary flags.
Wall-Mount / House-Bracket Poles
A standard house-bracket flagpole is typically 5–6 feet long and carries one 3x5 flag. These setups are generally not designed for two stacked flags. The short pole length leaves almost no room for a second flag below the first without it dragging or bunching. If you want to fly a state or military flag alongside your U.S. flag on a house mount, the better solution is a second bracket and pole mounted below the first, or a crossarm bracket. See the Accessories collection for bracket and mounting options.
For a fully outfitted dual-flag example, the 5-Section 6FT Stainless Steel Flagpole Kit ships with dual spinning rings already installed, which is a useful reference for understanding how a proper two-flag hardware configuration looks from the factory.
Half-Staff and Spacing: Two Rules Most Guides Skip
Half-staff: When a presidential or gubernatorial proclamation orders the U.S. flag to half-staff, the second flag on the same pole must also be lowered to half-staff. The U.S. flag is always raised first and lowered last, that protocol does not change with a second flag present.
Flag spacing: For smaller flags (3x5 and under), allow roughly 12–24 inches of clear vertical space between the bottom edge of the U.S. flag and the top edge of the second flag. For larger flags (5x8 and up), consult your pole manufacturer, as the flags need more clearance to unfurl without overlapping. Do not let the flags touch; contact causes accelerated fraying on both.
Common Mistakes to Avoid
- Buying a 4x6 state flag to go with a 3x5 U.S. flag. This is the single most common purchasing error. It makes the secondary flag larger than the primary flag, which violates the U.S. Flag Code. Always size the second flag equal to or smaller than the U.S. flag.
- Skipping the combined-area check. Just because both flags fit on the halyard does not mean the pole can handle the wind load. Calculate total square footage and compare it to your pole's single-flag maximum before flying.
- Using plastic snap hooks for large flags. Plastic clips fail faster under the added stress of two flags. For flags 4x6 and larger, use metal spinning rings or stainless steel snap hooks rated for outdoor loads.
- Forgetting to adjust spacing when raising and lowering. If the flags were positioned close together during initial setup and then re-hoisted without checking, they can tangle and tear within a single windy afternoon.
- Assuming a house-bracket pole can carry two stacked flags. It generally cannot. A 5–6 ft wall mount has room for one 3x5 flag, full stop. Plan a second pole or crossarm instead.
- Not lowering the second flag to half-staff. If a proclamation lowers the U.S. flag, the second flag comes down to half-staff as well. Leaving it at full staff while the U.S. flag is at half-staff misreads the display.
Frequently Asked Questions
What size state flag goes with a 3x5 American flag on a 20-foot pole?
A 2x3 state flag is the correct size to pair with a 3x5 U.S. flag on a 20-foot pole. The 2x3 is one standard size smaller, keeps the combined flag area well within the pole's wind-load capacity, and ensures the U.S. flag remains visibly larger as required by the Flag Code.
Can the second flag be the same size as the U.S. flag?
Technically yes, as long as the U.S. flag stays on top and the pole can handle the combined wind load. In practice, going one size smaller is the safer and more widely recommended approach, especially on residential poles 25 feet or shorter. Matched sizes work better on taller commercial poles with heavy-duty shafts, but always verify the pole's rated capacity first.
Do I need special hardware to add a second flag to my existing pole?
Yes. An external-halyard pole needs a second set of snap hooks or spinning rings on the same rope. An internal-cable pole needs a second flag arranger plus a quick link. A telescoping pole may need manufacturer-specific parts. Do not assume your existing single-flag hardware will hold two flags safely, the added weight and wind resistance require proper fittings rated for dual-flag use.
Where does the POW/MIA flag go when flying with the U.S. flag?
The POW/MIA flag flies directly below the U.S. flag on the same pole, or on a separate pole at a lower position. It should be the same size or smaller than the U.S. flag. At federally designated locations it has a specific precedence position (just below the U.S. flag and above other flags); for residential display the same hierarchy applies.
What happens to the second flag when the U.S. flag is at half-staff?
Both flags must be lowered to half-staff. The U.S. flag is raised to the top first, then lowered to the half-staff position. The second flag follows. When retrieving, raise both to the top first, then lower the U.S. flag last. The U.S. flag always holds positional precedence throughout the raising and lowering ceremony.