How do I run a germination test?

Place 10 or 20 seeds on a damp paper towel, fold it over, and keep it in a warm spot (65–75 °F / 18–24 °C). Check daily for sprouts. Count sprouted seeds after the typical days-to-germinate window for your crop (usually 5–14 days). Enter those numbers here.

What is a good germination rate?

Above 80% is generally considered good for fresh seeds. Rates of 60–79% are acceptable but you should sow more densely. Below 60% means the seeds are aging or were stored poorly — buy fresh seed if possible.

How does germination rate affect how many seeds I should sow?

Divide your target seedling count by the germination rate (as a decimal). For example, if you need 50 plants and your rate is 0.70 (70%), sow at least 72 seeds (50 ÷ 0.70 = 71.4, round up).

Why do germination rates vary by species?

Some crops (onions, parsnips) have naturally short seed viability and lower rates even when fresh. Others (tomatoes, peppers) remain viable for 4–5 years under good storage. Temperature, moisture, and seed maturity at harvest all affect the rate.

Does the packet seed count include enough extra for low germination?

Seed packets are sized for average germination rates, not worst-case. If your test shows a rate below the crop typical, buy an extra packet or sow the entire packet to compensate for losses.

What temperature is best for germinating seeds?

Most vegetables germinate best between 65–85 °F (18–29 °C). Cold-weather crops like lettuce and spinach germinate well at 45–65 °F (7–18 °C). Peppers and eggplant need 80–90 °F (27–32 °C) for best results.

Germination Rate Calculator

Enter seeds planted and seeds sprouted to get germination rate, then estimate how many seedlings a full packet will produce.

Germination Test Results

Seeds planted

Total seeds placed in your test (10 or 20 is standard).

Seeds sprouted

Number that showed a visible sprout.

Packet Yield Estimator (optional)

Seeds per packet

Leave blank to skip yield estimation.

Enter your test counts and click Calculate.

Typical Germination Rates — Common Vegetables & Herbs

Fresh seed under optimal temperature. Rates drop with age and poor storage.

Crop	Typical Rate	Days to Sprout	Viability (yrs)

Summary

The Germination Rate Calculator divides the number of sprouted seeds by seeds planted to give you a germination percentage. Enter your test count or full packet count and sprouted total to instantly see the rate. The packet yield estimator then projects how many seedlings you can expect from any packet size at that rate. A reference table lists typical germination rates for 20+ common vegetables and herbs so you can benchmark your results.

How it works

Enter the number of seeds you planted in your germination test.
Enter how many of those seeds actually sprouted.
The calculator shows germination rate as a percentage and a quality rating.
Optionally enter a packet seed count to estimate expected seedling yield.
Review the reference table to compare your rate against typical values for your crop.

Use cases

Test old seed packets before dedicating bed space to them.
Decide how densely to sow when germination rate is low.
Calculate how many packets to buy to hit a target seedling count.
Compare germination rates across seed brands or storage conditions.
Benchmark fresh seed purchases against published germination standards.
Track year-over-year viability of saved seeds.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu