How to Use This Calculator
This tool walks you through the complete cost journey from the moment you fill a barrel to the moment a bottle ships. Enter your barrel and aging details on the left, your costs on the right, and your results update instantly.
- Barrel & Aging: Enter fill volume, new-make proof, how long you plan to age, and your expected annual angel's share rate for your climate.
- Barrel proof at dump: Estimate the proof after aging (typically higher than fill proof in dry climates as water evaporates faster than alcohol; lower in humid climates). Adjust if you've done a test barrel.
- Target bottling proof: Usually 80 proof (40% ABV) for whiskey. The calculator works out exactly how much water to add.
- Costs: Enter your new-make spirit cost per gallon/litre, barrel price, monthly warehousing per barrel, labor, glass, labels, and other packaging.
- TTB Tier: Select the correct federal excise tax bracket. Most craft distilleries producing under 100,000 proof gallons per year qualify for the $2.70/PG craft rate.
- Target Margin: Set your desired gross margin and the calculator shows the minimum price to achieve it.
When and Why to Use This
Craft distillers often underestimate the true cost per bottle because individual costs (spirit, barrel, storage, taxes, packaging) are tracked in separate spreadsheets — if at all. This tool consolidates them into a single per-bottle COGS figure, which is essential for:
- Pricing decisions — setting a wholesale or DTC price that actually covers costs
- Barrel program planning — comparing a 5-gallon small barrel vs. a 53-gallon barrel's cost-per-bottle
- Investor / lender reporting — showing realistic product COGS
- Distributor negotiations — understanding your floor price before agreeing to margin splits
Formula & Method
Angel's Share: Volume after aging = Fill Volume × (1 − annual loss rate)^(months ÷ 12)
Dilution to bottling proof: Water to add = Post-aging volume × (barrel ABV ÷ bottling ABV − 1)
(Pearson square approximation — verify with hydrometer)
Net bottled volume: Post-dilution volume × (1 − bottling loss %)
Bottle count: Net bottled volume ÷ bottle size (converted to same unit)
Proof gallons (for FET): Post-aging US gallons × (barrel proof ÷ 100)
FET per bottle: (Total proof gallons × FET rate per PG) ÷ bottle count
COGS per bottle: Spirit cost + barrel amortization + storage + labor + glass + labels + other + FET
Min. sell price: COGS ÷ (1 − target margin)
Source:
TTB Tax and Fee Rates (CBMA permanent, verified 2025);
Distiller Magazine COGS Framework. This tool is an estimate for planning; always verify proof with a calibrated hydrometer before bottling.
Frequently Asked Questions
What is the angel's share and how much should I expect to lose?
The angel's share is the portion of spirit that evaporates through barrel staves during aging. Loss rates vary significantly by climate: roughly 2% per year in cool, humid regions like Scotland; 3–5% in temperate US climates; 6–8% in warm, humid areas; and 10% or more per year in very hot climates like parts of India or Texas in summer. Smaller barrels lose proportionally more because they have a higher surface-area-to-volume ratio — a 5-gallon barrel ages and evaporates much faster than a 53-gallon standard barrel. Humidity also matters: dry climates lose more water (raising proof), while humid climates lose more alcohol (lowering proof).
What is the TTB federal excise tax rate for craft distillers?
Under the permanent Craft Beverage Modernization Act (CBMA), qualifying domestic craft distillers pay $2.70 per proof gallon for the first 100,000 proof gallons removed per calendar year. The rate rises to $13.34/proof gallon for the next 22,130,000 proof gallons, and $13.50/proof gallon above that. A proof gallon is one liquid gallon at 100 proof (50% ABV) at 60°F. For a small batch distillery, the craft rate saves roughly $10.64 per proof gallon versus the standard rate — a significant cost advantage. This calculator applies the correct rate based on your tier selection.
How do I calculate how much water to add to reach bottling proof?
Use the dilution formula: Water to add = Volume × (Barrel ABV ÷ Target ABV − 1). For example, 40 gallons at 65% ABV diluted to 40% ABV: 40 × (0.65 ÷ 0.40 − 1) = 40 × 0.625 = 25 gallons of water. Important: alcohol and water don't mix perfectly additively due to molecular contraction (the mixture is slightly smaller than the sum of its parts). This calculator uses the Pearson square approximation, which is accurate for most planning purposes. Always take a calibrated hydrometer or Anton Paar reading on the final blend before bottling. Use RO or distilled water to avoid introducing minerals or off-flavors.
How many 750 mL bottles does a 53-gallon barrel yield?
It depends heavily on angel's share loss and your bottling proof. A 53-gallon barrel aged 2 years at 4%/year annual loss leaves about 49 gallons. Diluted from 65% ABV to 40% ABV, the volume expands to roughly 80 gallons. After a 3% bottling loss (~77.6 gallons), that yields about 390 standard 750 mL bottles. At higher barrel proof (70% ABV) and longer aging (4 years, 4%/yr loss ≈ 45.4 gal), diluted to 40% ABV yields about 76.6 gal × 0.97 ≈ 74 gal ≈ 374 bottles. Use this calculator to run your specific numbers exactly.
What is a proof gallon and why does it matter for excise tax?
A proof gallon is one US liquid gallon of spirits at exactly 100 proof (50% ABV) at 60°F — it's a measure of pure alcohol content, not volume. The TTB uses proof gallons (not wine gallons) to calculate federal excise tax on distilled spirits. To convert: Proof Gallons = Wine Gallons × (Proof ÷ 100). So 10 gallons at 80 proof = 8 proof gallons. At the craft rate of $2.70/PG, that batch owes $21.60 in FET. Because FET is assessed at the proof you dump (barrel proof, before dilution), always calculate proof gallons from your barrel dump volume and proof, not the post-dilution volume.
Should I use a 5-gallon or 53-gallon barrel?
Small barrels (5–10 gallons) age 5–10× faster due to higher wood-to-spirit contact, which can bring a product to market in months rather than years. However, the per-bottle barrel cost is much higher because the barrel cost is amortized over far fewer bottles. A $120 five-gallon barrel might yield only 18–25 bottles versus a $300 fifty-three-gallon barrel yielding 350+ bottles. Use this calculator with different fill volumes and barrel costs to compare the per-bottle economics directly. The flavor profile also differs — small barrels often produce more tannic, wood-forward spirits.
Does FET apply to spirits sold directly from the distillery (DTC)?
Yes. The TTB federal excise tax applies to all spirits "removed from bond" for consumption or sale, including direct-to-consumer (DTC) sales from your tasting room. The tax is owed by the Distilled Spirits Plant (DSP) regardless of the sales channel. State excise taxes and sales taxes are additional and vary by state. This calculator models the federal TTB rate only — add your state's rate as a separate packaging or cost line if needed. Always consult a compliance attorney or TTB-authorized consultant for your specific situation.