Read the whole quotation before reading the number
The expression 0.90 SGD is incomplete as an exchange rate. It needs a denominator: for one yen, for one hundred yen, or for some other specified amount. Multiplying a bare number before recovering that denominator can create a hundredfold error while leaving a spreadsheet full of plausible-looking decimals.
This worksheet treats the denominator as an input, not a footnote. Every row names the currency being supplied, its quantity, the currency being received and the quoted amount. It keeps that source direction even when the calculation needs its reciprocal. The original record stays visible beside the derived result.
Why the Singapore table is a useful unit check
The MAS exchange-rate page distinguishes Singapore dollars per one unit for USD, EUR and GBP from Singapore dollars per one hundred units for JPY and other listed currencies. A reader copying USD and JPY columns therefore has two different base quantities to preserve. The worksheet’s fictional example deliberately uses that distinction.
The same page describes its figures as informational averages of interbank buying and selling quotations around midday in Singapore, obtained from Refinitiv. They may differ from dealer quotations. This supports a reference-data comparison; it does not turn a displayed number into a price at which a particular account can transact.
Choose the direction of the question
Here the question is how many JPY correspond arithmetically to one USD, using SGD as the intermediate currency. The first leg already says SGD per USD. The second source row says SGD per one hundred JPY, so it must be normalised and reversed before it can supply JPY per SGD.
The tool finds the required pair regardless of the row’s orientation. It rejects a missing pair, an extra currency or duplicate pair rather than choosing whichever row comes first. USD→SGD and SGD→USD are two descriptions of the same required pair, not two different legs of the triangle.
Cancel the units before comparing the answers
In the example, 0.90 SGD for 100 JPY becomes 0.009 SGD per JPY. Its reciprocal is 100/0.90 JPY per SGD. Multiplying 1.35 SGD per USD by that reciprocal cancels SGD and produces exactly 150 JPY per USD. No assumption about a token peg or a contract multiplier is involved.
The independent direct record says 149 JPY per USD. Subtracting direct from via gives +1 JPY per USD. Dividing that difference by 149 and multiplying by one hundred gives about +0.67114094%. The sign describes this particular ordering of two entered references. Reversing the comparison would change the question.
| Entered record | Normalised meaning | Role |
|---|---|---|
| 1 USD = 1.35 SGD | 1.35 SGD per USD | First leg |
| 100 JPY = 0.90 SGD | 0.009 SGD per JPY | Reverse for second leg |
| 1 USD = 149 JPY | 149 JPY per USD | Direct comparison |
A shared date is a necessary label, not a shared instant
Daily references can use different collection windows, sources or valuation methods even when their printed dates agree. This tool requires all three rows to carry the selected daily date so that a known date mismatch is not hidden. Passing that check proves only consistency of the entered labels.
Weekly or monthly averages are withheld rather than mixed with a daily figure. The MAS page also describes when its weekly and monthly averages are released. Do not infer a missing daily observation from a neighbouring average. If the provenance is only a screenshot with no date, leave the date unknown and retain the unresolved comparison.
Missing evidence does not become a favourable rate
A blank quoted amount is unknown, not zero. Zero is rejected for a rate because reversing it would be undefined. A blank source reference also withholds the comparison even when the arithmetic could be performed. All three records remain in the report, so the missing item can be fixed without reconstructing the original inputs.
An explicit zero starting quantity has a different meaning: a known hypothetical amount of zero. It does not rescue missing rate evidence. Once every required rate is supported under the worksheet’s rules, multiplying by zero produces known zero output quantities while the per-unit rate comparison remains available.
Keep exact arithmetic alongside a readable display
The calculation uses exact decimal inputs and reduced fractions internally. Each intermediate division retains its denominator; it does not round the first leg before multiplying the second. The visible result rounds to eight decimal places, while the CSV retains exact fractions for a separate arithmetic check.
A very small nonzero difference may round to a displayed zero. That is a presentation limit, not proof that two references are identical. Inspect the fraction when that distinction matters. More displayed digits do not improve the underlying evidence or recover precision that the original table never supplied.
A triangle discrepancy is not a trading result
The two routes produce hypothetical quantities from reference inputs. The tool has no bid/ask spread, dealer acceptance, fees, quantity limits, funding constraints or execution timestamps. It cannot tell whether either route could be completed, let alone whether a positive arithmetic difference could be captured.
Use the discrepancy to check copied units, reversed pairs, date selection and source definitions. Do not relabel it profit or automatically change an account balance. A large difference may be a unit error; a small difference may reflect different reference conventions. The worksheet cannot choose an explanation without further evidence.
Preserve the route and the unfinished questions
Export keeps each source row, multiplier, date, evidence reference and issue, followed by the exact and rounded derived values. Formula-like text is escaped for spreadsheet use. Changing an input clears the previous export until the calculation is run again, which prevents an old result being copied under new inputs.
No rate request, account connection or document upload occurs. The arithmetic example and unit table remain usable without JavaScript. After completing the comparison, the optional link leads to this site’s separate English-language crypto signals and Telegram updates offer; following it is not required to use or export the worksheet.
Worked examples
Example 1
Fictional records: 1 USD = 1.35 SGD and 100 JPY = 0.90 SGD imply 150 JPY per USD via SGD. The separate direct record is 149 JPY per USD. The difference is +1 JPY per USD, or +0.67114094% of the direct record after rounding. For 1,000 USD, the two arithmetic outputs are 150,000 and 149,000 JPY, a difference of 1,000 JPY. Fees, executable quotes and profit remain unknown.
Inspect example inputs
{
"base": "USD",
"bridge": "SGD",
"quote": "JPY",
"quantity": "1000",
"date": "2026-10-19",
"as_of_date": "2026-10-20",
"rows": "from|to|base_units|quoted_amount|rate_date|frequency|reference\nUSD|SGD|1|1.35|2026-10-19|daily|DEMO USD record\nJPY|SGD|100|0.90|2026-10-19|daily|DEMO JPY record\nUSD|JPY|1|149|2026-10-19|daily|DEMO direct record"
}Questions about the method
Why not multiply the two copied MAS numbers directly?
Their unit directions differ. A per-100 JPY quotation must first keep its denominator and be inverted when the desired leg is JPY per SGD.
Does the date check prove the rates were simultaneous?
No. A date can cover different observation windows and sources. Intraday timing and executable prices remain unknown.
Can a tiny displayed zero be a nonzero difference?
Yes. The display rounds to eight decimal places; the CSV retains the exact reduced fraction.
Primary sources and scope
- Monetary Authority of Singapore — Exchange RatesChecked 2026-10-21. Per-one USD/EUR/GBP versus per-100 JPY and other listed currency labels; informational interbank-reference caveat; stated timing for weekly/monthly averages. No current rate values imported.
Examples explain a method. They do not predict prices or establish where a trading service is available. Check the named source before relying on future schedules.