How the tools are built

Sources first. Every calculator begins with a published regulation, a DoD rate sheet or an official finance page, never a forum post or a rule of thumb. Each tool page lists its sources at the bottom, with links.

Tested before it ships. Automated tests hold each calculator to its source, and the publishing script runs them before every release, so a failing test stops the site going out. What the tests cover depends on the tool:

• The weight allowance tests check every grade in JTR Table 5-37, with and without dependents.
• The OHA tests compare each country's header figures (the utility allowance, the move-in lump sum and the rate of exchange) and one sample locality's ceilings, column by column, with DTMO's workbook, then run hand-worked cases across all 8 countries.
• The PPM tests are cases worked out by hand, step by step, in the order the FMR settles a claim.

Dated and watched. Every tool carries two dates: when its data took effect and when we next expect it to change. Once a day a scheduled job compares the second date with today and alerts us to anything overdue.

Your inputs stay in your browser. The arithmetic happens on your own device, and the tools don't send what you type to us or anyone else. As you change a field, the tool writes your inputs into the page address, so any link you copy or share shows them.

Where the rules come from

• The Joint Travel Regulations (JTR), Chapter 5: the weight allowance (Table 5-37 and par. 051304), and how a personally procured move is paid and how much can be advanced (par. 051502).
• The DoD Financial Management Regulation (FMR), Volume 7A, Chapter 26: how OHA's rent, utility and move-in parts are figured.
• The FMR, Volume 9, Chapter 6 and Volume 7A, Chapter 45: PPM settlement, tax withholding and which pay is subject to FICA.
• DFAS's PPM page: the 22% federal rate on the incentive and the list of expenses it does and doesn't allow.
• DTMO's OHA rate sheets, one per country: rent ceilings by grade and locality, plus each country's utility allowance, move-in amount and exchange rate.

How OHA rates stay current

Each country's rates carry the date of the DTMO sheet they came from, and those dates differ from country to country. When DTMO posts a newer workbook, we update that country's rates by hand; nothing downloads new rates on its own. The daily check expects a new sheet on the date DTMO has already announced, if it has announced one. Otherwise it expects one a month after the current sheet's date, or, if that month had already passed when we last looked at DTMO's workbooks (September 19, 2026), a month after that look. Every OHA result shows the date of the sheet behind it, so you can see how fresh the number is.

The regulations and DFAS

The JTR, FMR and DFAS pages behind the PPM calculator are read again every quarter, and the next reading is due in December 2026. The weight allowance table follows the JTR revision that took effect September 1, 2026, and is next due for review on January 1, 2027. When a check turns up a change, the tool, its page and its dates are updated together, and the change goes on What changed.

Rounding

• OHA, local currency: amounts are kept in whole yen, euros, won, pounds, dinars or dollars. Where 90% of a ceiling or 75% of a utility allowance leaves a fraction, it's rounded half up.
• OHA, dollars: the estimate is the local amount times the exchange rate printed on that country's sheet, rounded half up to the cent.
• PPM: withholding and the advance limit are figured to the cent, rounded half up. We found no published rounding rule for these, so half up is our choice.
• Weight allowance: no rounding is needed. Every figure is a whole number of pounds taken straight from the JTR.

Inferences are labelled

Sometimes the sources don't settle a question and the tool still has to do something. When that happens, the tool page says the answer is our own reading, explains how we got there, and tells you what to check. The FICA section of the PPM (DITY) page is one example. Where the sources are silent and a guess would matter, the tool tells you to ask your finance or transportation office instead of guessing.