Hop Dosing Calculator

Calculate IBU with the Tinseth formula, build multi-addition hop bills, explore hop utilization, and plan dry hopping rates for your homebrew.

Tinseth IBU Calculator

Calculate bitterness units (IBU) for a single hop addition using the widely-used Tinseth formula.

Hop Amount (grams)

Alpha Acid (%)

Batch Volume (liters)

Original Gravity (SG)

Boil Time (minutes)

IBU = ( AA% · W_g · U · 1000 ) ÷ ( V_L · 4.15 ) where U = bigness · boil_time_factor; bigness = 1.65 · 0.000125^(SG-1); boil_time_factor = (1 - e^-0.04·t) ÷ 4.15

Multi-Addition IBU Builder

Add multiple hop additions, pick from common varieties (AA% auto-fills), and see the total IBU breakdown.

Batch Volume (liters)

Original Gravity (SG)

Hop Variety	Amount (g)	AA %	Boil (min)	IBU

Hop Utilization Chart

Tinseth utilization factors (U × 100%) at various boil times and wort gravities. Higher gravity worts extract less bitterness; longer boils extract more.

Reading the chart: Each cell shows the percent of alpha acids isomerized into the wort. A 60-minute boil at 1.050 SG yields roughly 21% utilization; doubling boil time to 90 minutes only adds ~3 percentage points.

Dry Hopping Calculator

Estimate total dry hop mass, aroma intensity, and hop oil contribution. Dry hopping adds aroma, not bitterness.

Batch Volume (liters)

Dry Hop Rate (g/L, typical 0.5-3)

Contact Time (days)

Temperature (°C)

Biotransformation tip: Adding dry hops during active fermentation (around days 2-4 of fermentation, while yeast is still active) can trigger biotransformation — yeast enzymes convert glycosidic-bound hop compounds into free aroma compounds, producing more tropical, fruity character. This works best at temperatures above 16°C.

About Hop Bitterness & Aroma

Hops contribute two main things to beer: bitterness (from isomerized alpha acids, extracted during the boil and measured in IBU) and aroma/flavor (from volatile hop oils, captured with late and dry-hop additions). The Tinseth formula is the modern homebrew standard for predicting IBU because it accounts for both boil time and wort gravity.

Bittering vs. Aroma vs. Dry Hop Timing

60-90 min boil — bittering; alpha acids isomerize, oils boil off.
10-20 min boil — flavor/aroma; partial bitterness, some oils preserved.
0-5 min / flameout / whirlpool — aroma; minimal bitterness, oils captured.
Dry hop (post-fermentation) — pure aroma; no measurable IBU contribution.

Target IBU by Style

Style	Typical IBU
Lambic / Gueuze	0–10
Witbier / Hefeweizen	8–20
Pilsner (Czech / German)	25–45
Pale Ale / Amber	25–40
IPA (American)	40–70
Double IPA	60–100
Imperial Stout	50–90

Frequently Asked Questions

What is IBU in beer?

IBU stands for International Bitterness Units, a measure of the iso-alpha acids dissolved in finished beer. One IBU equals one part per million (1 mg/L) of isomerized alpha acids. Most beers fall between 5 and 120 IBU.

How does boil time affect bitterness?

Longer boil times extract more bitterness because alpha acid isomerization is time- and temperature-dependent. Hops boiled for 60 minutes yield roughly 25-30% utilization, while a 10-minute addition only reaches about 6-8%. Flameout and whirlpool additions add aroma with little bitterness.

Tinseth vs Rager vs Daniels IBU formulas?

The Tinseth formula (Glenn Tinseth, 1995) is the modern homebrew standard and tends to give lower, more accurate IBU estimates for typical batch sizes. The Rager formula (Jackie Rager) predates Tinseth and overestimates IBUs in hop-forward beers. The Daniels formula (Ray Daniels) is a middle ground. Most brewing software uses Tinseth by default.

What is first wort hopping (FWH)?

First wort hopping means adding a portion of your bittering hops to the kettle before the boil begins, while the wort is still running off from the mash tun. FWH hops steep in hot wort at lower pH for an extended period, producing a smoother bitterness and often a small utilization bonus compared to a standard 60-minute addition.

How much dry hopping should I use?

Typical dry hop rates are 0.5 to 3 g/L (about 2 to 11 g per gallon). Lower rates (0.5-1 g/L) add subtle aroma for lagers and lighter styles, while 2-3 g/L or higher is common for IPAs. Contact time is usually 3 to 7 days at cool temperatures to minimize grassy off-flavors.

What is hop stand / whirlpool hopping?

Hop stand (or whirlpool) hopping means adding hops after flameout while the wort is still hot (typically 70-90°C). It extracts aroma oils with minimal bitterness. Because the Tinseth formula assumes a rolling boil, a common approximation is to treat whirlpool time at half its actual duration when calculating IBU.

Does higher gravity wort reduce bitterness?

Yes. The Tinseth formula includes a "bigness" factor that decreases utilization as gravity rises. A 1.090 barleywine extract significantly less bitterness per gram of hops than a 1.040 session beer boiled for the same time. This is why big beers need more hops.

Do dry hops add IBU?

Practically, no. Dry hopping adds hop aroma and some flavor, but the contribution to measurable IBU is typically under 5 IBU even at high rates. The oils added are not isomerized alpha acids (those require boiling).