GHS–USD: QASH reference calculation

A worked calculation of the common-reference relationship using explicitly supplied QASH reference values. The preset figures are illustrative; operational values require a current authorized publication.

Publication status

Published by the OpenForex Society, the standard-setting core of the OpenForex Foundation, as part of its established standards service to the open standards community.

Version

0.3.0

Last Updated

2026-10-23

Inputs and scope

How can an amount in one instrument be expressed in another when both already have values against the same reference unit?

The  symbol denotes the QASH reference unit. Both reference values in the calculation use one common scale and one stated input set. Fees, spreads and slippage are handled separately by an executing service. Decimal arithmetic preserves the specified numeric policy.

Calculation

First express the source amount in :

120.00 GHS x 0.50 /GHS = 60.00 

Then divide by the reference value of one USD:

60.00  / 6.00 /USD = 10.00 USD

Units cancel at each step. The calculated amount is 10.00 USD under the stated reference values and output policy.

Consistency checks

Reversing these inputs without fees gives 10.00 USD times 6.00 /USD, divided by 0.50 /GHS, or 120.00 GHS. This exact reversal follows from these numbers; it is not a general promise of lossless conversion after rounding.

If the USD reference value changes to 8.00 /USD while other inputs stay fixed, the output becomes 7.50 USD. This demonstrates sensitivity to supplied reference values. It does not explain how those values should be determined.

Invalid cases

A zero USD denominator makes the calculation undefined and must fail. Missing quote direction makes interpretation ambiguous. A negative reference price is outside this example's domain. Mixed snapshots require a separate policy.

Using authorized reference values

For operational use, obtain both reference values from the same QASH Valuation Authority publication. Preserve the epoch, reference direction, methodology version, observation version, validity period and integrity signature. The authority publication status identifies current availability; the reference calculator records the values entered and their provenance.

See the TVX standard, simulation methods, and QASH overview.