Reconcile barrels on hand for the period and work out the federal excise tax on what you removed, at the CBMA reduced rate. Enter gallons, barrels or kegs. Nothing leaves your browser.
Ending inventory is beginning inventory plus beer produced and received, minus beer removed taxpaid, removed without tax and lost. If you enter a measured ending figure, the gap shows up, which is how a carry-forward slip gets caught before it lands on next period's report.
Federal excise on beer removed taxpaid: a domestic brewer making 2,000,000 barrels a year or less pays $3.50 a barrel on the first 60,000 barrels removed in the calendar year and $16.00 a barrel above that (TTB tax rates). One barrel is 31 US gallons; a half-barrel keg is 0.5, a sixth-barrel 1/6.
Filing frequency follows the expected annual tax: not more than $1,000 may file the excise return annually, not more than $50,000 quarterly, above that semimonthly (27 CFR 25.164). Check TTB's own guidance before you file; this page is arithmetic, not tax advice.
Barrel Report reads your brew-log spreadsheet or POS export, reconciles the barrels against last period and lays out the report of operations and excise figures for you to review and file. $49/mo, first month free for early signups. No payment now.