How We Build Our Tools

1. Data Sources

• Gas Mark temperatures:Standard UK baking references (Gas Mark 1 = 140°C … Gas Mark 10 = 245°C), cross-checked against mainstream UK baking sources.
• Unit conversions:Internationally agreed SI / imperial factors (e.g. 1 lb = 0.45359237 kg exactly).
• VAT rates:Official HMRC (UK) and EU member-state published standard rates.
• Shoe sizes:Standard EU/UK/US size charts.

2. Conversion Formulas

Each tool shows its formula on the tool page. Two common patterns:

// Linear (e.g. weight, length): result = input × factor
1 lb = 0.45359237 kg

// Non-linear lookup (e.g. Gas Mark): exact table, not a formula
Gas Mark 4 ↔ 180°C ↔ 350°F ↔ 160°C (fan)

• UK-specific detail:fan-assisted oven temperatures are 20°C lower than conventional, because circulating air cooks faster — we handle this, most US sites don't.
• UK vs US gallon:the UK (imperial) gallon ≈ 4.546 litres, the US gallon ≈ 3.785 litres — they are NOT the same. Our unit tools use the correct one per context.

3. Privacy

• All calculations run in your browser's JavaScript. Inputs are never sent to a server.
• No accounts, no calculation history stored server-side.
• GDPR-friendly by design.

4. Update Cadence

• VAT and currency rates:reviewed regularly (currency shown is indicative, not real-time, unless stated).
• Each tool page shows its "last updated" date.
• Conversion factors (fixed by definition) rarely change.

5. Not Professional Advice

• VAT and tax tools are for estimation only — not tax advice. Confirm with HMRC or a professional for filings.
• Currency conversions are indicative — confirm with your bank or card provider for actual transactions.