Arm's length range builder
Turn a set of comparable margins into quartiles, a range and a verdict.
Open itA five per cent mark-up on cost and a five per cent margin on sales are not the same thing, and quoting one against the other is how benchmarks get misread. This prices both on your numbers and converts each into the other.
The service or manufacturing entity
$
The costs the mark-up applies to. Be explicit about whether pass-through costs are inside or outside it.
%
Profit as a percentage of the cost base.
%
Profit as a percentage of the price. Deliberately the same figure by default, so the difference is visible.
Difference in price between the methods
—
Which prices higher —
Net margin target is arithmetically possible —
Price on cost plus—
Profit—
Which is this margin on sales—
Price on the net margin target—
Profit—
Which is this mark-up on cost—
Mark-up equivalent to your target margin—
Margin equivalent to your mark-up—
The same profit, two denominators
Cost plus measures profit against cost. A net margin measures the same profit against the price. Because the price includes the profit, the margin is always the smaller number: an eight per cent mark-up on cost is a 7.4 per cent margin on sales, and an eight per cent target margin on sales needs an 8.7 per cent mark-up on cost to reach it.
On a small mark-up the gap looks trivial. On a 30 per cent mark-up it is not: that is a 23 per cent margin, and a benchmark study quoting 30 per cent margins would be describing an entirely different level of profitability. The conversion rows are there so the two never get mixed up in the same file.
When each method is the right one
Cost plus fits a contract service provider or a toll manufacturer whose value added really is its own cost base, and it needs reliable gross-margin comparables and consistent cost accounting across the sample. A net margin method fits where gross-margin data is not comparable — different accounting for cost of sales, different functional profiles — and is more tolerant of those differences because it measures further down the income statement.
The choice also decides what you have to be able to prove. Cost plus makes the composition of the cost base the battleground; a net margin makes the operating expense line and the treatment of non-operating items the battleground instead.
Worked example
A cost base of 4 million. The same headline figure of eight per cent is applied first as a mark-up on cost and then as a target margin on sales.
- Cost plus prices at 4.32 million, giving 320,000 of profit — a 7.41% margin on sales.
- The eight per cent margin target prices at 4.348 million, giving 347,826 of profit — an 8.70% mark-up on cost.
- The gap is about 28,000 on this base, from one word in the benchmark description.
Raise both figures to 30% and the gap widens to roughly 500,000. Reading a margin as a mark-up is not a rounding error at that level.
What this calculator assumes
- Both methods are run on the same total cost base. Where your policy excludes pass-through costs from the mark-up base but includes them in the price, model those costs separately.
- A net margin at or above 100% of sales is arithmetically impossible and the readout says so rather than printing a number.
- The conversions between mark-up and margin are exact and assume no other income or expense sits between the two lines.
- Nothing here selects the method for you. That depends on the functional analysis and on which comparable data is reliable.
An estimate, not advice. This is an estimate built from what you typed, not advice on your file. Nothing here reads your documents, checks your treaty article or looks at the year you are actually in. Where the number matters, we agree a fixed fee in writing before any work starts.
Where these figures come from
- current guidelines OECD Transfer Pricing Guidelines — transfer pricing methods
- current guidance India — transfer pricing methods, Income Tax Department
- current guidance United States — transfer pricing, IRS
Any figure prefilled in the panel above is stated with the year it belongs to and can be changed. Rates and thresholds move; a calculator that asks you for the current one stays right, and one that hides a guess does not.
Files that look like this one
Case study 1
An IRS Notice for a Year the Client Believed Was Settled
Most notices are proposals rather than assessments, and they carry a response window that is shorter than it looks. The engagement reads what is actually being proposed, gathers the support, and replies inside the window with the position rather than a request for time.
Read how this one runs
Case study 2
Residency Changed Mid-Year and Both Returns Assumed a Full One
A move part-way through a year produces two part-year positions, not two full ones. The engagement establishes the date residence actually changed, allocates income either side of it, and amends whichever return was filed on the wrong footing.
Read how this one runs
Case study 3
A Company Abroad Owned by a US Person
A business incorporated where the owner lives is a foreign corporation to the IRS, with a reporting package of its own and schedules that need local accounts restated. Classification comes first, because it decides what is reportable and when profits are taxed.
Read how this one runs
Case study 4
Treaty Relief Claimed on a Cross-Border Estate
The estate article can extend a proportionate credit where the two systems would otherwise both tax the same asset. Claiming it requires a valuation and a disclosure the estate may not expect to make.
Read how this one runs
Case study 5
A US Citizen Settled in India, Filing on Both Sides
Residence in India and citizenship in the United States produce two annual returns for one income. The order decides the credit, and the Indian financial year and the US calendar year have to be reconciled before either is prepared.
Read how this one runs
Case study 6
A Retirement Plan That Grows Tax-Deferred in Only One Country
Cross-border retirement accounts are recognised by treaty, but the deferral usually has to be elected rather than assumed. The engagement checks whether the election was made, makes it where it was missed, and reports the account on whichever side requires it.
Read how this one runs
Case study 7
A Penalty Argued on the Facts Rather Than the Form
Reasonable cause is a documented story with dates, not an assertion of good intent. The engagement assembles what the client actually knew and when, and puts the sequence in writing alongside the filings it explains.
Read how this one runs
Case study 8
Paying a Dividend Up to a Foreign Parent
The withholding rate depends on the treaty, on the size of the holding, and on whether the parent is the beneficial owner rather than a conduit. Establishing all three before the payment is what secures the lower rate at source.
Read how this one runsAll case studies — every published engagement in one place.
Core International & Cross-Border Tax Services
International Tax Planning & Advisory
Strategy and compliance for income, assets and families spread across borders.
One coordinating team: filings on every side of the border are sequenced so treaty relief and foreign tax credits are claimed once — and in the right country.
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Dual filers: U.S. citizens in Canada and Canadians with U.S. income run two parallel systems — we prepare both, in the right order, every year.
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The move year is its own project: the elections and valuations filed that year decide the next decade of both countries’ returns.
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Default withholding is 25% of gross: elective returns routinely turn over-withheld rent and pensions into refunds.
Transfer Pricing & BEPS
Documentation prepared with the return is the cheapest insurance in international tax; reconstructing it during an audit is the most expensive.
Tax Treaties & Withholding
Relief is only as good as the paperwork claiming it — we build treaty positions that survive review on both sides.
Cross-Border Estates & Trusts
Wills drafted for one country routinely misfire in the other — deemed disposition here, estate tax there, credits in between.
Global Investments & Reporting
Information returns carry the sharpest penalties — $25 a day whether or not any tax is owing. We keep them clean and on time.
Cross-Border Corporate Tax
Expansion raises the same four questions every time — entity, PE, repatriation, payroll. We answer them before the tax authorities do.
India Tax for NRIs & Returning Residents
The deduction is taken on the sale price, not the gain — which is why an NRI property sale strands cash unless the certificate is applied for before closing.
Canadian Tax with a Foreign Element
Residency is decided on facts, not on a form — and the year you arrive or leave is the one where the largest amounts turn on the smallest details.
UAE Tax for Expats & Their Home Country
A zero-tax country is only half the answer — the question that decides the bill is whether the country you came from still treats you as resident.
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Technology & SaaS
Software revenue crosses borders by default — sourcing rules, withholding on licence-like payments and IP location decide the effective rate.
Software revenue is rarely taxed where the team sits. Licence, subscription and service income are characterised differently by each side, and the answer decides withholding at source, treaty relief and whether a foreign customer creates a taxable presence at all — questions that are cheap to settle before the contract and expensive afterwards.
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Professional Services Firms
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Cross-Border Real Estate
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Importers, Exporters & Manufacturers
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Athletes, Artists & Entertainers
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Remote Workers & Digital Nomads
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Investment Funds & Holding Companies
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