Calculation Methodology

JavaScript/TypeScript numbers are double-precision binary floats (IEEE 754). Without guards, dividing by zero returns Infinity or NaN, causing layout crashes or silently wrong outputs.

// Guard: impressions must be a positive number
if (!impressions || impressions <= 0) {
  return { cpm: 0, perImpression: 0 };
}

// Guard: cost must be non-negative
if (cost < 0) {
  return { cpm: 0, perImpression: 0 };
}

const cpm           = (cost / impressions) * 1000;
const perImpression = cost / impressions;
return { cpm, perImpression };

This pattern is applied uniformly across every solver function. The return shape is always typed — no undefined values propagate to the UI layer.

Traditional marketing tools are strictly one-directional. SeeCalc derives all rearrangements of each formula algebraically so every variable is solvable — not just the canonical output.

All derivations are verified to be mathematically reciprocal — substituting any solved value back into the base formula returns the original inputs exactly (subject only to float precision bounds defined in Section 03).

Raw float arithmetic produces trailing precision noise (e.g. 0.1 + 0.2 === 0.30000000000000004). Each metric category applies a fixed rounding rule at the display layer without altering intermediate computation.

Rounding is applied only at the display boundary (toFixed / Intl.NumberFormat). All intermediate calculations retain full float precision to prevent compounding rounding error across chained formulas.

All metric definitions follow IAB (Interactive Advertising Bureau), MMA Global, and common SaaS industry standards. Definitions are pinned — they do not change based on platform, campaign type, or geography.

All user inputs pass through a staged validation pipeline before reaching any solver function. Validation is non-blocking — invalid inputs surface contextual error text rather than preventing further interaction.

Marketing data frequently contains values that are technically valid inputs but produce mathematically degenerate results. Each edge case below has a defined handling contract.

Every formula on SeeCalc passes a four-stage review before deployment. No calculator ships without completing all four stages.