Space Marine Costume
For the Emperor! Suit up in massive, battle-worn power armor.
The Space Marines, or Adeptus Astartes, are the legendary superhuman defenders of humanity in the Warhammer 40,000 universe. Choosing this costume makes an undeniable statement at any convention or Halloween event, showcasing massive, imposing armor plates and heavy weaponry. The signature look consists of oversized power armor, a grilled helmet, and a devastating boltgun.
- Difficulty
- Advanced
- Time
- ~180 min
- Budget
- $150–2000
Try it on
See yourself as Space Marine
One clear photo of yourself; we render you in this costume — face untouched, full body, about 20 seconds.
One render, $1. No account needed — if it fails you're not charged. Pricing.
Your photo is sent to Google's Gemini API to make the render and isn't used for training. Renders are AI-generated and labelled.
Want a different costume on this photo, or a whole group in costume? Open the Try-On Studio.
What you need for a Space Marine costume
Short on time? Buy it ready-made
Spirit Halloween sells the complete Space Marine costume — one box instead of 6 pieces.
Space Marine Helmet
A full-head helmet with a prominent grilled mouthpiece, circular ear vents, and glowing green or red T-shaped visor lenses.
DIY: Modify a motorcycle helmet with EVA foam panels and paint it to match your armor color.
Oversized Shoulder Pauldrons
Massive, curved shoulder guards made of thick EVA foam or molded plastic, painted in your chosen Chapter's colors.
DIY: Cut and heat-shape 10mm EVA foam into large half-dome shapes, adding trim around the edges.
Power Armor Chestpiece
A bulky, mechanical torso plate featuring an imperial aquila (double-headed eagle) or skull emblem on the chest.
DIY: Layer EVA foam over a compression shirt, detailing the chest with a foam-cut skull or eagle emblem.
Gauntlets and Greaves
Thick, blocky forearm and shin guards that create an exaggerated, superhuman silhouette.
DIY: Wrap cylindrical EVA foam pieces around your forearms and shins, securing them with Velcro straps.
Prop Boltgun or Chainsword
An oversized, blocky sci-fi rifle (bolter) or a sword with a chainsaw blade, heavily weathered.
DIY: Construct a blocky rifle shape out of cardboard or insulation foam, adding a thick PVC pipe for the barrel.
Under-Armor Bodysuit
A black ribbed or textured compression shirt and pants to wear beneath the armor plates.
DIY: Use a plain black long-sleeve shirt and matching athletic tights.
Rather not assemble it? See ready-made Space Marine costumes at Spirit Halloween ↗
How to put it together
- 1
Put on the black under-armor compression shirt and pants as your base layer.
- 2
Secure the shin greaves and thigh guards using the internal Velcro straps, ensuring you can still bend your knees.
- 3
Strap on the chest and back plates, adjusting the shoulder straps so the torso sits comfortably on your shoulders.
- 4
Attach the massive shoulder pauldrons to the chest plate harness using heavy-duty Velcro or buckles.
- 5
Slide on the forearm gauntlets and don a pair of black tactical gloves.
- 6
Put on the full-head Space Marine helmet, checking that you have adequate ventilation and visibility through the visor.
- 7
Equip your prop boltgun or chainsword, and practice your heavy, imposing warrior stance.
Makeup & hair
Keep hair flat or wear a wig cap so the helmet fits comfortably. If going helmetless, style your hair in a severe military buzzcut or slicked-back look, and use gray makeup to draw battle scars on your face.
Space Marine for couples, groups, kids & more
- couples
- Pair up as a Space Marine and a Sister of Battle or an Adeptus Mechanicus Tech-Priest.
- group
- Gather a squad representing different Chapters, such as Ultramarines (blue), Blood Angels (red), and Imperial Fists (yellow).
- kids
- A simplified version using a printed fabric jumpsuit with foam-padded shoulders and a lightweight plastic mask.
- Plus size
- The bulky, oversized nature of power armor is highly accommodating; scale up the EVA foam templates for a comfortable, imposing fit.
Tips
- Power armor gets hot quickly; install small, battery-operated computer fans inside the helmet to keep cool.
- Build your armor with flexible joints or gaps behind the knees and elbows so you can actually sit down.
- Use acrylic paints and a dry-brush technique with metallic silver to add realistic battle damage and scratches to the armor edges.
- Wear thick-soled boots or platform shoes to add extra height and match the superhuman proportions of a Space Marine.
Space Marine costume FAQ
- What is the easiest way to make Space Marine armor?
- Using EVA foam sheets (like interlocking gym floor mats) is the most popular and budget-friendly DIY method. You can find printable PDF templates online to trace, cut, heat-shape, and glue the armor together.
- How heavy is a full Space Marine costume?
- If built from EVA foam, the entire suit is surprisingly lightweight, usually under 15 pounds. However, the bulkiness can make movement tiring over long periods.
- Can I buy a pre-made Space Marine costume?
- Fully assembled, high-quality Space Marine armor is typically custom-made by commission and can cost upwards of $1,500. Budget-friendly options usually consist of licensed vacuformed plastic masks and printed chest pieces.
Did you know? In Warhammer 40k lore, Space Marines stand over seven feet tall and possess nineteen specialized organ implants, including a secondary heart and a third lung.