Why These Calculators Exist
Military pay is mathematically complicated. Base pay is the visible line on the LES, but the real economic value of military service includes BAH, BAS, Tricare, the BRS retirement match, the 20-year pension, the GI Bill, MSRRA tax advantages for spouses, deployment programs like SDP and the combat-zone tax exclusion, the no-down-payment VA loan, commissary and Exchange savings, and a handful of other benefits that don't appear on a single statement.
Civilian financial calculators don't model any of this. Generic rent-vs-buy calculators ignore BAH. Salary calculators ignore the tax-free treatment of allowances. PCS calculators don't exist in civilian software at all because PCS isn't a civilian concept.
The seven calculators on this page exist to fill that gap. Each is free, signup-optional, built from official sources, and covers a specific question military families repeatedly ask.
Which Calculator Should I Use?
A quick decision tree based on the question you're trying to answer:
- "How much will my TSP be worth at retirement?" → TSP Calculator
- "Should I take this civilian job offer or stay in?" → Salary Calculator
- "My spouse works in [state]; do we owe state tax there?" → Spouse Tax Wizard
- "What will I get reimbursed for this PCS?" → PCS Planner
- "How much will SDP earn me on this deployment?" → SDP Calculator
- "Should I buy a 2-4 unit property with a VA loan?" → House Hacking Calculator
- "Does shopping at the commissary actually matter?" → On-Base Savings Calculator
Our Standards
Every calculator follows the same standards:
- Official sources only. DFAS pay tables, JTR for PCS rules, DTMO for per diem, IRS for tax rules, DoD for BAH, TSP.gov for fund returns, DeCA for commissary methodology, 10 U.S.C. § 1035 for SDP. Each calculator page lists its sources at the bottom.
- Conservative messaging. No "guaranteed savings of $X" claims. The calculators give you the math; whether the dollar outcome materializes depends on your situation. We'd rather under-promise on dollar amounts and over-deliver on accuracy.
- Visible last-reviewed date. Every calculator page shows when it was last reviewed against the underlying rates. When DFAS, BAH, or per diem rates change, the calculators get updated within days and the date moves forward.
- No PII storage. The calculators run client-side for the inputs that matter. We don't collect, sell, or share what you type. (See Privacy Policy for details.)
When a Calculator Isn't Enough
Calculators answer numeric questions. They don't answer situation-specific questions like "does the JTR allow me to do X on this PCS?" or "how does this exact MOS pay interact with combat-zone exclusion?"
For those, we built Ask the Military Expert — a RAG-backed assistant that answers in roughly 30 seconds with citations to DFAS, JTR, IRS, and DoD official sources. Five questions per month are free; unlimited access is the paid product. It's the bridge from "here's the math" to "here's what to actually do given my situation."
We also publish the Monthly Military Financial Briefing — one email a month covering pay-table releases, BAH adjustments, tax changes, and the planning moves military families actually use. No fluff, no hype, no Family Finance content masquerading as military advice.
Who Built This
Garrison Ledger is built by a one-person team focused on the problem military families repeatedly hit: financial questions that don't have civilian parallels and don't get answered well by either generic personal-finance content or official military communications. The calculators here are the free baseline; the paid product is the deeper assistant.
If you find an error, an out-of-date rate, or a calculator methodology that needs revisiting, send a note via the contact page. Corrections get prompt attention and the next calculator page review picks them up.
Every Free Calculator at a Glance
- TSP Calculator — Model BRS matching, fund allocations, and retirement growth using TSP.gov historical returns. (TSP calculator · BRS match · TSP fund allocation)
- Military Salary Calculator — Compare military total compensation (base, BAH, BAS, Tricare, retirement) to a civilian offer in any state. (military salary calculator · military vs civilian pay)
- Spouse Tax Wizard — MSRRA, residency, and state-tax workup for military spouses. Plain English, IRS- and DOR-cited. (MSRRA calculator · military spouse state tax · SLR)
- PCS Budget Planner — Estimate DLA, TLE, per diem, MALT, and PPM profit from current JTR rates and DTMO per diem. (PCS calculator · DLA TLE per diem · PPM DITY profit)
- SDP Calculator — Project Savings Deposit Program returns: 10% guaranteed on $10,000 with the 90-day grace period. (SDP calculator · 10 USC 1035 · deployment savings)
- House Hacking Calculator — Model a 2-4 unit VA loan purchase: rental income, BAH coverage, PITI, vacancy reserves, and break-even. (VA loan multifamily · house hacking military · BAH rental)
- On-Base Savings Calculator — Project annual commissary, Exchange tax-free, and MILITARY STAR fuel savings using DeCA's published methodology. (commissary savings · Exchange tax free · MILITARY STAR)