Chia Plot Calculator: How Many Plots Fit Your Drive

A Chia plot calculator works out how many plots you can store on a given drive, how much total plot space you have, and how long plotting will take based on your hardware. You enter your drive capacity, plot size, and the number of parallel plots you plan to run, and it returns the number of plots, usable space, and estimated time. This guide explains the math behind the calculator, how to choose the right plot size, and common pitfalls to avoid.

Formula

The core formula is simple: Number of plots = floor(Drive capacity / Plot size). Here:

• Drive capacity (d) – the raw storage size in gigabytes (GB) as reported by the drive manufacturer (e.g., 4000 GB for a 4 TB drive).
• Plot size (p) – the actual size of one plot in gibibytes (GiB). A standard k32 plot is 101.4 GiB, but k33 is 208.5 GiB, k34 is 428.8 GiB, and k35 is 881.3 GiB.
• Number of plots (n) – the integer result, since you cannot store a fraction of a plot.

Note the difference between GB and GiB: 1 GB = 1,000,000,000 bytes, while 1 GiB = 1,073,741,824 bytes. Drive manufacturers use GB, but Chia plots are measured in GiB. A 4 TB drive (4,000 GB) actually holds about 3.64 TiB, which is why you can’t simply divide 4,000 by 101.4.

Worked Example

Using the defaults from the calculator: a 4000 GB drive, 101.4 GiB plots, and 4 parallel plots.

1. Convert drive capacity to GiB: 4000 GB ÷ 1.073741824 = 3725.29 GiB.
2. Divide by plot size: 3725.29 ÷ 101.4 = 36.74.
3. Take the floor: 36 plots.
4. Usable space: 36 × 101.4 = 3650.4 GiB.
5. Free space in GB: 3725.29 – 3650.4 = 74.89 GiB ≈ 80.4 GB (or about 0.08 TB).

The calculator gives 36 plots, 3650.4 GiB used, and 74.9 GiB free (displayed as GB in the output). That matches the manual calculation.

Why Plot Size Matters

Chia plots come in different sizes, called k-values. The most common is k32 (101.4 GiB), but you can make larger plots with k33, k34, etc. Larger plots have a slightly better chance of winning per byte, but they take longer to create and require more RAM and temporary space. The calculator lets you adjust the plot size to see how many fit on your drive. For example, a 4 TB drive holds 36 k32 plots, but only 17 k33 plots (3725.29 ÷ 208.5 = 17.87 → 17).

How to Choose Your Plot Size

Your choice depends on your hardware and goals:

• k32 – standard, works on most machines, minimum RAM 4 GB (though 8 GB is recommended).
• k33 – uses about 2× the RAM and temporary space of k32, but gives a small farming efficiency boost.
• k34 and above – require significant RAM (16+ GB) and time; rarely used by home farmers.

If you have a large drive (16 TB or more), you might prefer k33 to reduce the total number of plot files, but the trade-off is longer plotting time. Use the calculator to compare how many plots you’d get with each size.

Plotting Time and Parallel Plots

The calculator also asks for the number of parallel plots. While it doesn’t compute time directly (because it depends on CPU, RAM, disk speed, and software), you can estimate total time by multiplying the time per plot by the number of plots and dividing by the parallelism factor. For example, if one plot takes 6 hours and you run 4 in parallel, you can produce about 4 plots every 6 hours, so 36 plots would take about 54 hours (36 ÷ 4 × 6).

Keep in mind that parallel plotting can saturate your CPU and disk I/O. If you push too many parallel plots, each one slows down, and the total time may not improve. A common rule of thumb is to run one parallel plot per CPU core, but also ensure you have enough RAM (about 4 GB per plot).

Common Mistakes and Misconceptions

• Mixing GB and GiB – Always use GiB for plot size. A 4 TB drive is 4000 GB, not 4096 GiB. The calculator’s output shows free space in GB, which can confuse if you’re comparing to drive specs.
• Rounding down – You cannot store 36.74 plots; always round down. The calculator does this automatically.
• Overprovisioning – Some drives have hidden reserved space (e.g., for file system metadata). It’s wise to leave 2–3% free, so if the calculator says 36 plots, you might only safely store 35.
• Plot size is not the same as file size – The actual file on disk may be slightly larger due to filesystem overhead, but the plot size is the standard measure.

Limits of the Formula

The formula assumes a perfectly formatted drive with zero overhead. In reality, file systems (NTFS, ext4, etc.) consume a small percentage of space for metadata, and the drive’s usable capacity is less than the advertised GB. Also, if you’re using a drive that is also your OS drive, you’ll have less free space. The calculator gives a theoretical maximum; always leave a buffer.

Frequently Asked Questions

How many plots can I fit on a 1 TB drive?

Using k32 plots (101.4 GiB), a 1 TB drive (1000 GB) has about 931.3 GiB of usable space. Dividing by 101.4 gives 9.18, so you can fit 9 plots. In practice, you might fit 9 with about 20 GiB left over.

What is the difference between k32 and k33 plots?

k33 plots are larger (208.5 GiB vs 101.4 GiB) and take about twice as long to create. They have a slightly higher chance of winning per byte, but the increase is marginal. Most farmers stick with k32 because it’s faster to plot and easier on hardware.

How much RAM do I need for plotting?

For k32 plots, the minimum is 4 GB, but 8 GB is recommended. For k33, you need at least 8 GB, but 16 GB is safer. The calculator doesn’t account for RAM, but you should check your system’s specs before running parallel plots.

Can I use a calculator to estimate plotting time?

This calculator only computes storage counts. For time, you need to know your hardware’s plotting speed. A typical k32 plot takes 5–10 hours on a modern CPU with an SSD for temporary space. Multiply by the number of plots and divide by the number of parallel plots to get total time.

Why does my drive show less space than advertised?

Drives are marketed in GB (1,000,000,000 bytes), but operating systems report GiB (1,073,741,824 bytes). This is why a 4 TB drive shows as 3.63 TB in Windows. Also, the file system and manufacturer’s hidden recovery partition take up space.

Should I leave free space on a plotting drive?

Yes. Leave at least 2–3% free to avoid performance degradation and file system errors. If the calculator says 36 plots, consider only storing 35 to be safe.

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in d | Drive capacity | GB | 4000 | 0
in p | Plot size | GiB | 101.4 | 0
in par | Parallel plots | - | 4 | 1
out n | Number of plots | - | floor(d / p) | 0
out used | Usable plot space | GiB | n * p | 1
out free | Free space left | GB | d - n * p | 1