Measure Without Tools (Body Units)

Summary

Before you have rulers, you can still build reproducibly by using your body as a consistent measuring system. Your “units” will differ from other people’s, but they will be repeatable for you if you stay consistent.

This article defines a small set of body-based units and a simple way to make a durable reference so you can repeat dimensions across projects.

Prerequisites

• None (Level 0).

Units (choose a set and stick to it)

Pick a small set you will use everywhere:

• Finger width: width of your index finger (useful for small thicknesses).
• Thumb width: width of your thumb (useful for “thumb-thick” sticks).
• Palm width: width of your palm at the knuckles (good for small boards and bundles).
• Handspan: tip of thumb to tip of pinky with fingers spread.
• Cubit: elbow to fingertips (good for stick lengths and spacing).
• Pace: one normal step (good for distances and layouts).

Rule: avoid mixing units casually. If you write “arm-length” in one place, use “arm-length” again, not centimeters.

Steps

1) Make a reference stick (optional but recommended)

This is a simple way to repeat measurements across days and across tasks.

1. Find a straight, dry stick roughly forearm-length.
2. Choose one end as the “zero” end.
3. Mark handspans and palm-widths by notching or scratching the stick.
4. Mark smaller units (finger widths) near one end for convenience.

If you have no cutting tool, you can scratch marks with a sharp stone edge, a hard pointed pebble, or by rubbing gritty sand into the wood with pressure.

2) Use “counted units” in your notes

When you write instructions, write them like:

• “Spindle: 4 handspans long, thumb-thick.”
• “Notch opening: 2 finger widths wide at the outer edge.”

If you want to help modern readers too, you can add metric in parentheses, but keep the primary instruction body-based.

Verification

• Measure the same object three times on different days: you should get the same count of units each time.
• Two people using the same reference stick should get the same result.

Safety

• If you scratch/notch sticks with sharp stone edges, treat them as knives: cut away from your body and keep fingers behind the edge.

Troubleshooting

• My measurements drift: you are changing where you place your fingers/hand. Always start from the same “zero” end and use the same posture.
• Reference marks wear off: deepen the scratches, choose harder wood, or make multiple reference sticks.

Variants

• Cord reference: once you can make cordage, tie knots every palm-width and use the cord as a flexible measuring tape.