See your total weight in full plate armour — and find out if you'd still be able to walk.
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Total fighting weight
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What it was like to fight in plate armour
Hollywood\'s image of medieval armour — a knight clanking around, unable to mount his horse without a crane — is largely myth. Full plate armour from the 14th and 15th centuries weighed 22–32 kg total: heavy, but distributed across the entire body. Trained knights could run, climb ladders, swim, and mount horses unassisted while fully armoured. The real problem wasn\'t weight — it was heat.
Inside a steel suit at full sun in summer, body temperature could rise 1°C every ten minutes of activity. Heat exhaustion killed more armoured knights than enemy weapons. Battle accounts repeatedly describe knights collapsing from heatstroke before the fighting was decided.
Frequently asked questions
How much did medieval armour actually weigh?
A full suit of late-medieval plate armour weighed 22–32 kg — heavy but well-distributed across the body. Tournament armour was thicker and heavier (40–50 kg) but rarely worn into actual combat. The "knight needs a crane to mount his horse" myth comes mostly from 19th-century novels.
Could knights actually move in plate armour?
Yes — surprisingly well. Modern reenactment experiments and historical fencing manuals show that armoured knights could run, leap, swim, and mount horses unassisted. The Royal Armouries in Leeds has filmed armoured volunteers doing all these things.
What killed knights in armour?
Heatstroke, blunt-force trauma through the armour (warhammers and pollaxes were specifically designed for this), and being forced to the ground and stabbed through visor slits with thin daggers (the "misericorde"). The armour worked — but it also exhausted you.
Armour evolved continuously across the Middle Ages, getting heavier as metallurgy improved and steel became cheaper, then lighter again as firearms made heavy armour pointless.
Era
Armour type
Typical weight
9th–11th c.
Mail hauberk + helmet
10–15 kg
12th–13th c.
Mail + great helm + surcoat
15–20 kg
14th c.
Mail + transitional plate
20–25 kg
15th c. (peak)
Full plate (war)
25–32 kg
15th c.
Tournament plate
40–50 kg
16th–17th c.
Cuirass + helmet only
10–18 kg
Could a modern person survive a day in armour?
Realistically — not without training. Modern reenactors who fence in full harness describe it as the equivalent of carrying a 25 kg backpack while sprinting. After 20–30 minutes of fighting, even highly conditioned modern athletes are gassed. Medieval knights spent their entire adolescence training in increasing weights of armour, building cardiovascular fitness and specific muscular endurance from the age of 10 onwards. Without that lifetime of preparation, an average adult would manage perhaps 15 minutes of meaningful activity before exhaustion.
Famous armoured fighters
Henry V at Agincourt (1415): fought all day in full plate, killing several French knights personally. He was 28.
Joan of Arc (1429–1431): fought in custom-fitted white armour weighing approximately 23 kg.
Edward the Black Prince (1346): wore the famous black armour weighing around 28 kg through the Battle of Crécy at age 16.