When to Replace Your Razor Blades

Razor blade cartridges last 5 to 10 shaves for multi-blade cartridge razors (Gillette, Schick, Harry's) and 3 to 7 shaves for double-edge safety razor blades. Most men use a cartridge for 2-4 weeks depending on shaving frequency, though the optimal replacement is more frequent than most people practice. The blade edge is microscopically thin... about 50-80 nanometers at the cutting tip. Each pass across skin and hair chips and rolls this edge, progressively dulling the blade. Hair itself is harder than copper wire of the same thickness, so every stroke is genuinely wearing down the metal. Coarse, thick hair dulls blades faster than fine hair. Facial hair (which is coarser than body hair for most people) is harder on blades than leg shaving. Multi-blade cartridges (3-5 blades) seem like they'd wear faster because there are more blades per pass, but each individual blade does less work per stroke because the cutting load is distributed. The lubrication strip on cartridge razors is the first thing to go... it dissolves in 3-5 shaves, leaving you with less glide protection even though the blades still technically cut. Moisture and oxidation between shaves are actually what kills most razor blades. The thin edge corrodes when left wet. Rinsing the blade, shaking off water, and storing it in a dry place (not in the shower) extends blade life significantly. Some people store blades in mineral oil between shaves to prevent oxidation, which can double blade life.

Changing a cartridge razor head takes 2 seconds: press the release button, click on the new cartridge. No learning curve.

Switching to a double-edge safety razor has a 1-2 week learning curve. The technique is different from cartridge shaving: hold the razor at a 30-degree angle, use short strokes with no pressure (the weight of the razor does the work), and shave with the grain. Expect a few nicks during the first week... they stop once the technique clicks.

Loading a new blade in a safety razor takes 10-15 seconds: unscrew the handle, place the blade on the base plate, replace the top cap, and tighten. The blade is double-sided, so flip it after 3-4 shaves to use the other edge before discarding.

Pro tip for switching to safety razors: watch 2-3 YouTube tutorials before your first shave, and start with a mild blade (like Astra or Derby) rather than an aggressive one (like Feather).