Methodology

A deterministic engine

Every calculator on CalcFleet runs on the same principle: the same normalized input, formula version, dataset version, runtime profile and numeric profile produce the same output. There is no model in the loop deciding the number. A language model may help you phrase a question or read back a result, but the math is always done by a tested formula, never by the model.

Each tool is a pure function

A calculator is a pure function: given the same inputs it returns the same result, with no hidden state, no network calls and no randomness (simulations that need randomness declare an explicit policy). Intermediate values are accumulated at full precision and rounded only at the very end, under a declared rounding profile, so results do not drift from stray early rounding.

Inputs are validated before anything is computed

Every input passes through a schema before it reaches a formula. If a value is missing, out of range or the wrong type, the calculation is refused rather than producing a misleading number — you see a prompt to check your inputs, never a NaN on screen. The same schema defines the input and output shape used by the calculator page, the API and the MCP tool, so the three surfaces cannot disagree.

Tested against known cases

Formulas are covered by an extensive suite of automated tests — 2,400+ automated tests across the fleet. Each tool is tested against figures verifiable by hand, against its own internal consistency, and against inputs its schema must reject. A calculation is deterministic and reproducible under the inputs entered; that is not the same as being correct for your particular situation, and it is never a guarantee of an outcome.

Source-cited and versioned

Each calculator carries a methodology: the formula, its assumptions and limitations, the units and rounding profile, an effective period, and the sources behind it. Formulas are identified and versioned (for example v1.4.0), so a result can always be traced back to the exact formula that produced it. When a formula changes, its version changes with it.

Results are modeled under the assumptions you enter

Financial, health and business results depend on the assumptions you supply. CalcFleet reports what those assumptions imply — a modeled figure — not a promise about the real world. For the honest limits of what a calculation can and cannot tell you, see limitations.

Related

• Benchmark methodology — where the “vs median” comparison figures come from, and their known biases.
• Limitations — what a calculation does not tell you.
• Security — how we protect the platform and your inputs.