BOHN AI Research · Measurement Systems

The Royal Cubit
according to Axel Klitzke

Roll a circle with a one-meter diameter through one full turn, and its circumference unfolds to π m. Divide that length by six, and each segment is one royal cubit.

π m 1 RC
6 RC = π m
Scroll to see why
BOHN AI evaluates and contextualizes this thesis: the page analyzes Klitzke’s argument; it does not present a settled scholarly consensus.
Core Statement
52.36  cm
What is exact is not the rounded centimeter value, but the definition: 1 RC = π/6 m = 52.35987756 cm. The value 52.36 cm is that result rounded to two decimal places.

According to Axel Klitzke’s calculation framework, 52.36 cm is the logically consistent value for the royal cubit. The widely cited value of 52.38 cm comes from a different methodological line, primarily from measurement and rounding in the Petrie tradition. The two values are not simply right or wrong; they rest on different frameworks of justification.

The thesis in one paragraph

The royal cubit is
one-sixth of π meters

This yields 1 RC = π/6 m = 52.35987756 cm, rounded to 52.36 cm. This value differs methodologically from empirical convention values such as 52.38 cm. Mathematically, Klitzke’s value is coherent and rigorous; historically, the meter premise remains the central point to be tested.

The compass

Three levels that must be kept clearly separate

The debate over 52.36 cm and 52.38 cm can look like a rounding issue. In reality, it brings together three different ways of justifying a unit of measure. Separating them makes it possible to present Klitzke’s argument strongly without bypassing the historical burden of proof.

Mathematics
What follows from the equation 6 RC = π m?
Exactly: 1 RC = π/6 m = 52.35987756 cm. The division by six is straightforward.
Klitzke’s Model
How does Klitzke interpret the royal cubit within the measurement system?
An internally coherent model built around π, the meter, the centimeter, the Urzoll, and Giza geometry.
Archaeology & Metrology
What do measurements, cubit rods, and back-calculations show?
Empirical variation. No single modern centimeter value is compelled by the archaeological record alone.
The Derivation

From Circle to Cubit

Scroll down. The circle explains the mathematics step by step.

d = 1 m U = π m 1 KE = π/6 m
Step 1

The Circle

Take a circle whose diameter measures exactly one meter. Its circumference is C = π · d.

Step 2

The Circumference

With a diameter of one meter, the circumference is exactly π m, or about 3.1416 m.

Step 3

Six Equal Segments

The circumference is divided by six. Each of the six segments has the same length.

Step 4

One Royal Cubit

One segment is one royal cubit: 1 RC = π/6 m. Exactly 52.35987756 cm, rounded to 52.36 cm. The difference between the exact value and the rounded value is only 0.0012 mm per cubit.

The Derivation

From Circle to Cubit

The derivation requires only the circle formula. A circle with a diameter of one meter has a circumference of π m. Dividing that length by six gives one royal cubit for each segment.

01
U=π · d
The circumference of a circle is pi times the diameter.
02
d=1 mU=π m
For a diameter of exactly one meter, the circumference is pi meters.
03
1 KE=π6 m
Divide the circumference into six equal segments: one segment is one royal cubit.

Exact is exact; rounded is rounded.

Calling 52.36 cm exact misses the precision of the derivation. The correct statement is: 52.36 cm is the value of π/6 m rounded to two decimal places. The difference per cubit is tiny.

0.0012 mm Difference between exact and rounded value, per royal cubit
Two values, two worlds

52.36 cm or 52.38 cm

Both values are used, but they answer different questions. One is a geometric definition; the other is an empirical convention derived from building measurements.

π 3,14159265 the circle constant
6 · π/6 m 3,14159265 exact = π
6 · 52,36 cm 3,1416 rounded
6 · 52,38 cm 3,1428 convention

Multiplied by six, the exact definition reproduces π. The rounded value 52.36 cm gives 3.1416 m, the standard four-decimal approximation to π; 52.38 cm departs at the third decimal place.

Geometric Definition
52.36 cm
Klitzke · from 6 RC = π m
Circle Circumference π m ÷ 6

A definition from geometry. It stands or falls with the meter premise, but within that premise it is exact.

two worlds
Empirical Convention
52.38 cm
Petrie tradition · from measurement
Measurement 20.622 inches × 2.54

A back-calculated measurement value — 52.37988 cm precisely. It neither replaces Klitzke’s equation nor refutes it.

Petrie’s cubit values from different reference points. Conversion based on 1 inch = 2.54 cm.
Petrie reference Value in inches Conversion to cm
King’s Chamber base 20.632 52.40528
Passage lengths 20.622 52.37988
Pyramid base at 440 cubits 20.611 52.35194
Petrie’s cautious mean 20.620 ± 0.005 52.3748 ± 0.0127
Why tiny differences become large across long spans

Per cubit, the differences look negligible. Across long chains of measurement, especially in statements based on π approximations, they become noticeable. Against Klitzke’s exact value, the deviations shown below accumulate across 440 royal cubits.

Comparison value Deviation per RC Deviation at 440 RC
52.36 cm +0.001224 mm +0.54 mm
52.3748 cm +0.149224 mm +6.57 cm
52.38 cm +0.201224 mm +8.85 cm
In the monument

Where the value appears in the Great Pyramid of Giza

Klitzke traces the 52.36 cm value in specific structures, especially in the King’s Chamber and the sarcophagus. These are strong examples within the model, not independent historical proofs. They show why his system works with 52.36 cm and loses its patterns with 52.38 cm.

20 KE 10 KE 5,2 KE 13 / 50 37 / 50

The King’s Chamber

Basic dimensions: 20 RC in length and 10 RC in width. Dividing the north-south axis in a 37:13 ratio gives the smaller section as 13/50 of the length, or 5.2 RC.

5.2 · 52.36 cm = 272.272 cm

The rectangle 10 RC · 5.2 RC has an area of 52 RC².

outer · 33 RC inner · 27 RC

The Sarcophagus Code

The outer design dimensions give 33 RC; the inner dimensions give 27 RC. Together, that is 60 RC.

60 · 52.36 cm = 31.416 m ≈ 10π m

The same π relationship already embedded in the base equation appears again in the sarcophagus.

Interactive

The height of the Great Pyramid of Giza

Assuming an original height of 280 royal cubits. Per cubit, the difference between the values is tiny; over the full height, it adds up. Select a value.

146.608 m
280 RC at 52.36 cm
+0.3 mm compared with the exact value

Values from the research document (height at 280 RC). The bars show the deviation from the exact value: tiny per cubit, visible over 280 cubits.

φ

This 2:1 geometry of the King’s Chamber is also the origin of the BOHN AI design system: φ = 1.618 is derived from precisely this ratio. The page you are reading is laid out on the same principle as the monument it describes.

Assessment

What is exact, and what is interpretation?

For mathematicians, the central test is simple. From the premise 6 RC = π m, it follows that 1 RC = π/6 m exactly. The debate begins only with the question of whether that premise holds historically.

1 2 3 4 5 6
mathematically exacthistorically open
  1. 1 If 6 RC = π m holds, then 1 RC = π/6 m. Mathematically exact
  2. 2 1 RC = 52.35987756… cm. Decimal expansion of the exact value
  3. 3 1 RC ≈ 52.36 cm. Correct rounding
  4. 4 6 · 52.36 cm = 3.1416 m. Good approximation of π
  5. 5 Decimal patterns such as 5.2 RC = 272.272 cm appear. Correct with the rounded value
  6. 6 These patterns alone prove the ancient Egyptian use of the centimeter. Not historically proven
Deep dive: Where the decimal patterns really come from

The patterns are not magic; they arise from arithmetic. The rounded value 52.36 cm is the fraction 5236/100. Multiplied by 1.3, or 13/10, this gives:

1.3 · 52.36 = 1310 · 5236100 = 680681000 = 68.068

Because 5236 · 13 = 68068, the visible repetitions arise at multiples of 1.3 RC: 68.068 cm, 136.136 cm, 204.204 cm, and so on. This does not count against the model; it simply shows that the patterns are based on real decimal arithmetic. The next step — reading this arithmetic as a historical clue — is an additional interpretation.

This is precisely where 52.36 cm becomes much stronger than 52.38 cm: with 52.38 cm, 1.3 RC is not 68.068 but 68.094 cm, and 5.2 RC becomes 272.376 cm rather than 272.272 cm. The structure depends precisely on the 52.36-cm value.

Deep dive: The extended system of measure and the Urzoll

Klitzke’s royal cubit sits within a larger metrological model that includes the meter, centimeter, Urzoll, sacred cubit, and Hunab. This is not necessary for the core formula, but it explains why he does not view the cubit in isolation.

The Urzoll is especially revealing: 1 Urzoll = (1/0.3937) cm = 2.54000508… cm. This value is known in metrology; it corresponds to the old U.S. survey inch derived from the former survey-foot definition (1200/3937 m). According to NIST, the survey foot has been deprecated since 2023. The number is therefore not freely invented; what remains open is whether it may be interpreted as part of a much older order of measure.

Deep dive: The meter question, the central point to be tested

The decisive open issue is the meter question. Klitzke’s model assumes that the meter, or an equivalent length principle, was already operative in the building plan. Today’s meter is defined in terms of the speed of light. This openness does not weaken the mathematics; it marks the boundary between a computational model and historical proof.

Deep dive: Testability and falsifiability

A robust presentation makes the thesis testable. Competing cubit values must therefore be defined in advance, for example 52.34 cm, 52.35987756 cm, 52.3748 cm, and 52.38 cm. Then the same building dimensions should be compared using the same rounding rules, tolerances, and error analysis, including the dimensions that do not fit.

Only then can one test whether the Klitzke value performs significantly better on independent datasets than the empirical alternatives. This testability is not a weakness; it is a strength. A thesis that can be tested against alternatives is more convincing than a collection of impressive numerical examples.

Final conclusion
52.36 cm
= π/6 m

“52.36 cm is the mathematically necessary value if the royal cubit is defined as π/6 m. 52.38 cm is an empirical convention from a different derivation and does not refute this definition.”

Mathematically necessary once the equation is used as a definition. Historically, the meter premise remains to be tested.

1 RC Circumference = π m

Glossary

RC
Royal cubit. In this text, the royal cubit in the Klitzke model.
π
Pi, the circle constant. The ratio of a circle’s circumference to its diameter.
π/6 m
One-sixth of π meters. In the Klitzke model, the exact definition of 1 RC.
Working value 52.36 cm
Practical two-decimal rounding of the exact value 52.35987756 cm.
Conventional value 52.38 cm
An empirically back-calculated value from the Petrie tradition.
Urzoll
In Klitzke’s model: (1/0.3937) cm = 2.5400050800… cm; metrologically identical to the old U.S. survey inch.

Sources

  1. [1] Axel Klitzke: The Cosmic Order of Measurement Systems, Part 2. Royal Cubit, Sacred Cubit, and Hunab. hores.org
  2. [2] Axel Klitzke: The Cosmic Order of Measurement Systems, Part 1. Inch, Urzoll, and π relationships. hores.org
  3. [3] Axel Klitzke: The Phenomenon of the King’s Chamber in the Great Pyramid of Giza. hores.org
  4. [4] Axel Klitzke: Code of the Sarcophagus in the Great Pyramid of Giza. hores.org
  5. [5] Axel Klitzke: Geometry of the Giza Plateau. hores.org
  6. [6] W. M. Flinders Petrie: The Pyramids and Temples of Gizeh. London, 1883, Chapter XX. ronaldbirdsall.com
  7. [7] NIST: SI Units, Length. International inch definition: 25.4 mm. nist.gov
  8. [8] NIST: U.S. Survey Foot. Definition 1200/3937 m, deprecated since 2023. nist.gov
  9. [9] BIPM: SI base unit metre. Definition in terms of the speed of light. bipm.org
  10. [10] Ezekiel 40:5. Biblical reference to the measuring rod of six cubits.
  11. [11] Mark H. Stone: The Cubit, A History and Measurement Commentary. Journal of Anthropology, 2014. doi.org
  12. [12] Nora E. Scott: Egyptian Cubit Rods. The Metropolitan Museum of Art Bulletin, 1942.