Currency: the tool works in one currency at a time, AUD by default, and any currency is supported. Rates refresh automatically from a daily mid-market feed, and the date they were published shows next to the rate field. If the feed cannot be reached the tool falls back to its stored rates, which is why the rate always stays editable. For a currency not in the list pick "Other", type the code and rate, and hit Apply. Commodity benchmarks are USD spot, converted at the working rate. Switching currency converts every money field at these rates, so set currency and rate first and enter all figures, including the kit quote, in the working currency.

Commodity prices are USD benchmarks. Gold and silver refresh automatically from the same daily feed as the currency rates. The rest are stored defaults, last set 14 July 2026: gold ~$4,020/oz, silver ~$58.25/oz, copper ~$6.26/lb (COMEX), iron ore 62% Fe ~$98.86/t, zinc ~$3,616/t (LME), nickel ~$16,548/t (LME), Newcastle thermal coal ~$128/t. Markets move, so check before a meeting using the live price link that appears next to the price field for each commodity (Trading Economics). Every price is editable.

Machine specs come from public OEM data (Komatsu, Hitachi, Liebherr, Caterpillar published specifications). Bucket ratings vary by configuration (shovel vs backhoe) and site-specific buckets are common, so treat the preloaded capacity as a starting point and confirm it against your own fleet. The Cat 6040 figure is a class-typical estimate, so check it against your spec sheet.

Production model: tonnes per hour = bucket capacity × fill factor × loose material density × cycles per hour × operating efficiency. Loose (in-bucket) density defaults are set per commodity. Your actual dig rate always beats the model, so use the override field if you know it.

Commodity value converts grade, recovery and price into revenue per tonne of product mined. For iron ore and coal it uses product yield × price, reflecting direct-shipping style operations. These are deliberately simple models for a first conversation, not a resource statement.

Strip ratio is just this: how many tonnes of waste the machine moves for every 1 tonne of product it digs. At 2:1, one bucket in three earns money and the rest is overburden, so when the machine goes down, only the money-earning share of its digging counts as lost revenue. Waste time is valued at zero, which understates the true cost of waste delays (deferred access, resequencing, idle trucks), and that is deliberate: a conservative number survives scrutiny. Default 2:1. A dedicated ore digger feeding the crusher is 0. Your mine plan has the real ratio, so use it.

Incident cost defaults lean on ChromeGuard's company profile: roughly 12 hours of downtime per changeout, up to $50k in parts and labour, and up to $500k in lost revenue per incident, with "production actually lost" defaulted to 50% to stay conservative where fleets can partially catch up.

What this tool deliberately leaves out: safety exposure of the changeout itself (working under a raised boom is high-risk work), knock-on truck fleet idling, and contract penalty exposure. If any of them apply at your site, the case only gets stronger.