Axis

Trust & definitions

How Axis treats a measurement

A readable account of base representations, exactness, rounding, prefixes, regional differences, context, and dimensional limits.

01 · Foundation

Canonical units

Each compatible quantity is represented through one canonical base. A displayed relationship explains how the selected unit maps to that base; the interface does not rely on pair-to-pair lookup tables.

value in unit A → canonical dimension → value in unit B

02 · Display

Precision & rounding

Automatic precision balances meaningful digits and legibility. Fixed decimal places, significant figures, scientific notation, engineering notation, and fractions are display decisions—not changes to the underlying quantity.

Trailing digits are not extra certainty

An approximate source or historically variable definition remains approximate even when more digits are displayed.

03 · Scale

SI & IEC prefixes

Decimal SI prefixes scale by powers of 1,000 in digital storage. Binary IEC prefixes scale by powers of 1,024. The names and symbols remain visibly distinct.

1 MB

1,000,000 bytes · decimal SI

1 MiB

1,048,576 bytes · binary IEC

04 · Definitions

US, Imperial & regional systems

Shared names can hide different definitions. US and Imperial gallons, fluid ounces, customary tons, and survey measures receive explicit system labels before a result is shown.

  • US liquid gallon ≠ Imperial gallon
  • Mass ounce ≠ fluid ounce
  • Short ton ≠ long ton ≠ metric tonne

05 · Uncertainty

Historical units

Historic and regional units can vary by place, trade, authority, and period. Their pages state the assumed definition and use an approximate or historically variable label where one universal value would be misleading.

06 · Assumptions

Contextual conversions

Some useful transformations bridge dimensions only when an additional quantity is supplied. Axis names the missing context rather than silently choosing an assumption.

Mass ↔ volume

Requires density

Data ↔ duration

Requires transfer rate

Wavelength ↔ frequency

Requires propagation speed

Torque ↔ power

Requires rotational speed

07 · Reference scales

Logarithmic quantities

Decibel-based levels require the correct physical quantity and reference. They are formula-based relationships, not ordinary linear factors, and sound pressure level is not interchangeable with sound intensity level.

Lₚ = 20 log₁₀(p / p₀)

08 · Limits

Dimensional compatibility

Dimension signatures use exponents of length, mass, time, electric current, temperature, amount, luminous intensity, angle, and information. Direct conversions require matching signatures.