Where do AED pads go on an adult?
The standard position for adults is front and side: one pad on the upper right chest below the collarbone, and the other on the left side of the chest, in line with the middle of the armpit, a few inches below it.
The American Red Cross’s AED steps put the pads in the same two spots: high on the right side of the chest, and low on the left side, a few inches under the armpit. The AHA’s 2025 guidelines add a detail that matters: the side pad belongs on the mid-axillary line, the imaginary line running down the side of the body from the middle of the armpit, not around toward the front of the chest. The shock travels between the pads, so they need to sit on either side of the heart.
Every set of AED pads carries a picture of where it goes. Follow it: the Red Cross’s 2025 guidelines tell rescuers using an AED to follow the manufacturer’s placement. Some pad sets are made for one position only, and a few, such as ZOLL’s one-piece CPR-D-padz, place both electrodes in a single piece.
- Bare the chest. Remove or cut away clothing over the chest and sides.
- Wipe the chest dry if it’s wet or sweaty.
- Peel one pad from its backing and press it firmly onto the upper right chest, just below the collarbone and to the right of the breastbone.
- Peel the second pad and press it onto the left side, below the armpit, on the side of the chest rather than the front.
- Plug the pad cable into the AED if it isn’t already connected, and follow the prompts.
On a woman, the side pad goes on the side of the chest below the armpit, not on breast tissue: both the Red Cross and the AHA’s pad diagrams say pads shouldn’t sit on the breast. Adult pads are big, more than 8 cm (about 3 inches) across, so press the whole surface down for good contact with the skin.
Front-and-back pad placement
In the front-and-back (anteroposterior) position, one pad sits on the chest and its partner on the back, so the heart sits between them. It’s the standard for infants and small children, and an accepted alternative for adults.
For adults, the AHA’s 2025 guidelines treat front-and-side and front-and-back as equally reasonable. In one study of 207 patients the AHA cites, the first shock worked about equally often in either position, 82.1% against 82.2%. Another found more people regained a pulse with front-and-back placement but no difference in survival, and the AHA says more research is needed.
The Red Cross’s 2025 guidelines favor front-and-side for adults because it’s faster: you don’t have to roll the person over and stop CPR to place the back pad. When front-and-back is used for an adult, they describe the front pad on the left chest between the middle of the chest and the nipple (for women, to the left of the lower breastbone) and the back pad to the left of the spine, just below the shoulder blade.
Use front-and-back when your AED’s pads show it, when the person’s chest is too small for two pads side by side, or when you’ve been trained to. Otherwise, the front-and-side position on the pads’ pictures gets the shock started soonest.
AED pad placement on children and infants
On an infant or small child, center one pad on the chest and center the second on the back, between the shoulder blades. On a bigger child, the adult position works as long as the pads don’t touch.
The AHA’s 2025 pediatric guidelines say either front-and-back or front-and-side may be reasonable for infants and children, and list the best position as an open question. They say to use the largest pads that fit while keeping them at least 1 to 2 cm (roughly half an inch to three-quarters of an inch) apart. The Red Cross prefers front-and-back for infants and young children; its public pages tell rescuers to use it on every infant, and on a child whenever the pads would otherwise touch.
The AHA’s pediatric diagrams show three options:
- Front and back, centered: a pad centered on the bare chest and a second pad centered on the back.
- Front and back, on the left: the front pad on the left chest between the breastbone and the left nipple, the back pad on the left side of the back next to the spine.
- Front and side: one pad on the right chest just below the collarbone, the other on the left side on the mid-axillary line, keeping both off the breast tissue and the belly.
The international body that reviews resuscitation science, ILCOR, has asked AED makers to standardize the front-and-back diagram for infants and young children with the front pad over the left chest and the back pad just below the left shoulder blade, so follow your pads’ own picture. For children under 8, use child pads or the AED’s child setting if it has one; see our guide to pediatric AED pads for each model’s option.
Hair, water, implants, patches and jewelry
None of these stops you using an AED, but each changes how you place the pads. The goal is always the same: pads flat on bare, dry skin, away from metal and medical devices.
- Chest hair: the Red Cross says hair rarely keeps pads from sticking, so shaving usually isn’t needed. If very thick hair would stop the pads touching skin, quickly shave just the pad areas with the razor in the rescue kit.
- Water and sweat: get the person out of any water, then wipe the chest dry so the pads don’t go on wet skin. AEDs are safe to use in rain or snow; keep the AED itself dry. Skip alcohol wipes for drying: alcohol can catch fire.
- Pacemakers and implanted defibrillators: the Red Cross says an AED is safe to use. You can often see or feel the device as a lump under the collarbone, and a medical ID bracelet may mention it. Don’t put a pad directly over the device; shift the pad aside. If you can’t tell, place the pads as usual.
- Medication patches: nitroglycerin and nicotine patches, among others, can sit where a pad goes. Peel them off first, wearing gloves so the drug isn’t absorbed through your own skin.
- Jewelry and piercings: don’t delay the shock to remove them. Just keep the pads off metal.
- Bras: new in the AHA’s 2025 guidelines, it may be reasonable to move a bra aside rather than remove it, as long as both pads go on bare skin in the right place. The AHA notes that women get public-access defibrillation less often than men, and baring the chest may be part of the reason. In a study the AHA cites, pads placed right over a metal underwire still had 100% first-shock success, with no arcing or burns. The Red Cross’s 2025 guidelines agree, and add that if the bra still gets in the way of the pads or compressions, take it off.
- Clothing: pads never go over fabric. Cut or pull clothing away from the whole chest and both sides.
Pad placement mistakes to avoid
The most common mistakes are pads that touch, a side pad placed too far toward the front, and pads on wet skin or fabric. Delaying the shock to get placement perfect is a mistake too.
- Pads touching each other. On a small chest, switch to front and back instead.
- The side pad too far forward. The AHA puts it on the mid-axillary line, on the side of the chest, not near the breastbone.
- Pads on wet skin, over clothing, or only half stuck down. They need full contact with bare, dry skin.
- A pad over a pacemaker, a medication patch or metal jewelry. Move the pad or remove the patch.
- Child pads or the child setting on an adult. The Red Cross warns the shock would be too weak. Adult pads on a child are acceptable when there’s nothing else.
- Moving pads that are on the wrong sides. The Red Cross says the AED still works if they’re swapped. Leave them and follow the prompts.
- Long pauses in CPR. The AHA’s 2025 guidelines say to keep the pauses around the shock as short as possible. Place the pads while someone else keeps up compressions if you can.
- Expired or dried-out pads. The gel that carries the shock dries out over time. Check the date on every inspection; our guide to AED pad expiration explains why.
For the full sequence from collapse to EMS, see how to use an AED. To keep pads in date across every AED you manage, AED Log tracks pad and battery expiration and warns you before the date passes.
AED pad placement FAQ
Where do you put AED pads?
On an adult, one pad goes on the upper right chest below the collarbone and the second on the left side of the ribs, a few inches under the armpit. Follow the pictures on your pads, and put them on bare, dry skin.
What if the AED pads are on the wrong sides?
Leave them. The Red Cross says the AED still works if the pads are swapped, and moving them only delays the shock. What matters is that both are on bare skin and not touching each other.
Do you have to remove a bra to use an AED?
Not always. The AHA’s 2025 guidelines say moving the bra aside may be reasonable, as long as both pads are on bare skin in the right place. If it still gets in the way, the Red Cross says to remove it.
Is it safe to use an AED if the person has a pacemaker?
Yes. If you can see or feel the device, often a lump below the collarbone, don’t put a pad directly over it; move the pad aside. If you aren’t sure, place the pads as usual.
Where do AED pads go on a child?
If the pads would touch, center one pad on the chest, then center the second pad on the back. On a larger child, the adult position works if the pads stay apart. Use child pads or a child setting under 8.