Sompi to KAS: Kaspa's Smallest Unit, Explained With Examples

A sompi is the smallest unit of Kaspa. One KAS is 100,000,000 sompi, so one sompi is 0.00000001 KAS — eight decimal places, the same split as Bitcoin's satoshi. To convert sompi to KAS, divide by 100,000,000; to convert KAS to sompi, multiply by 100,000,000. Our sompi to KAS converter does it exactly, without the floating-point rounding that trips up spreadsheets and quick scripts.

This guide explains where you meet sompi, how to convert reliably, and how familiar Kaspa figures — like the block reward — look in both units.

Why the unit is called sompi

The unit is named after Yonatan Sompolinsky, whose research on PHANTOM and GHOSTDAG underlies Kaspa's consensus (see What Is BlockDAG?). The naming follows the tradition of Bitcoin's satoshi.

The conversion

KAS   = sompi ÷ 100,000,000
sompi = KAS × 100,000,000

Some examples:

A KAS amount can never have more than eight decimals. If a tool shows a ninth, it has a rounding problem.

Where you see sompi

APIs

The public Kaspa REST API returns amounts in sompi: balances (/addresses/{address}/balance), transaction outputs (amount), and the circulating supply (/info/coinsupply). Integers avoid the ambiguity of decimals; the cost is that you must convert before showing a number to a person.

The node's code

Kaspa's consensus code works in sompi throughout. The emission table that sets the block reward is a list of sompi-per-second values, starting at 44,000,000,000 (440 KAS) per second.

Explorers and wallets

Explorers and wallets usually convert to KAS for display, but some show sompi in detailed views. Our explorer shows KAS with up to eight decimals, so nothing is hidden by rounding.

The block reward in sompi

The block reward is a good example of why sompi matters. The node computes the reward per block as the table value divided by the number of blocks per second, rounded up to a whole sompi. Since May 2025 the network makes ten blocks a second, so:

• Month 54: table value 1,944,543,648 sompi per second → 194,454,365 sompi per block (1.94454365 KAS).
• Month 55: 1,835,404,799 sompi per second → 183,540,480 sompi per block (1.83540480 KAS).
• Month 66: 972,271,824 sompi per second → 97,227,183 sompi per block (0.97227183 KAS).

Notice the rounding: 1,944,543,648 ÷ 10 = 194,454,364.8, which rounds up to 194,454,365. That single sompi is why the reward twelve months later is "half, plus or minus a sompi" rather than exactly half per block. Our emission page shows rewards to all eight decimals for this reason.

Converting without rounding errors

Computers store most decimals in binary floating point, which cannot represent numbers like 0.1 exactly. Multiply 1.1 by 100,000,000 in many programming languages and you get 110000000.00000001 instead of 110000000. With large balances, the errors become visible.

Three safe methods:

1. Use integers. Keep amounts in sompi as integers (or big integers for very large totals) and only format them as KAS at the end.
2. Use string arithmetic. Split the KAS amount at the decimal point, pad the fractional part to eight digits, and join. That is how our converter works.
3. Use a decimal library that does exact base-10 arithmetic.

Large totals need care too: the circulating supply in sompi is a number with nineteen digits, larger than the biggest integer many languages can represent exactly in a standard number type. Our site keeps such values as strings until the moment it displays them.

Quick mental conversions

• Drop eight zeros: 250,000,000 sompi → 2.5 KAS.
• Count decimals: 0.00012 KAS has five decimals after the point; pad to eight → 12,000 sompi.
• Thousand-sompi chunks: 1,000 sompi = 0.00001 KAS. Fees on Kaspa are often small enough to be easier to read in sompi than in KAS.

Showing amounts to people

If you build anything that displays Kaspa amounts — a dashboard, a bot, a spreadsheet — a few habits prevent confusion:

• Store sompi, show KAS. Keep the integer for arithmetic and convert once, at the point of display.
• Trim trailing zeros, not significant digits. 1.50000000 KAS reads better as 1.5 KAS; 0.00000150 should stay 0.0000015, never 0.00.
• Say which unit you mean. A bare "194454365" is ambiguous; "194,454,365 sompi" or "1.94454365 KAS" is not.
• Group digits. Thousands separators make sompi figures readable at a glance.
• Keep the precision you were given. If the API returned an exact integer, do not round it on the way to the screen; show all eight decimals where a reader may need to reconcile a payment.

Fees in sompi

Kaspa fees are computed from a transaction's mass — a measure of the resources it uses — and are paid in sompi. When the network is not busy, the fee for an ordinary transfer is a small number of sompi per unit of mass, which in KAS terms is a tiny fraction of a coin. On our transaction pages, the fee is shown in KAS with all eight decimals, and only when every input amount is known; otherwise it is left blank rather than estimated.

Using the converter

Our tools page has two fields:

• Type a KAS amount (up to eight decimals) and the sompi field updates.
• Type a sompi amount and the KAS field updates.

When a live price is available, it also shows the US-dollar value at that price. The conversion between KAS and sompi itself never depends on the market — it is fixed by definition.

The same page has a mining estimator that uses the live reward and network hashrate; it works in KAS but is computed from sompi values underneath.

Worked examples

A wallet balance from the API. The balance endpoint answers {"balance": 38240000000}. Drop eight zeros' worth of places: 38,240,000,000 ÷ 100,000,000 = 382.4 KAS.

A payment you want to send. You want to send 12.75 KAS. In sompi that is 12.75 × 100,000,000 = 1,275,000,000. Done with string arithmetic: whole part "12", fractional part "75" padded to "75000000", joined to "1275000000".

A daily mining estimate. Suppose a miner's share of the network earns 0.864 blocks a day at a reward of 194,454,365 sompi. That is 0.864 × 194,454,365 ≈ 168,008,571 sompi, or about 1.68 KAS a day. The tools page does this with the live figures.

The circulating supply. The API reports it in sompi as a nineteen-digit integer. Divide by 100,000,000 for KAS — roughly in the tens of billions. If you parse that number as an ordinary float you may lose the last few digits; it does not matter for a headline figure, but it does if you are reconciling totals.

Why eight decimals?

Eight decimal places give a fine enough unit for very small payments and fees while keeping integer arithmetic simple. Bitcoin chose the same split, so tools and habits carry over: anyone used to satoshis can read sompi immediately. A smaller unit would make integer totals even longer without a practical benefit for a currency whose fees are already a small number of sompi per unit of mass.

Sompi in transactions

Kaspa uses unspent transaction outputs (UTXOs), like Bitcoin. Each output carries an amount in sompi and a script that says who may spend it. When you spend, your wallet picks outputs whose amounts add up to at least what you want to send plus the fee, and creates a change output back to you. On our transaction pages you can see each input's and output's amount; the difference between the two sums is the fee.

Because every output is an integer number of sompi, there is never a fraction of a sompi anywhere on the ledger.

Common mistakes

• Treating sompi as cents. There are 100,000,000 sompi in a KAS, not 100.
• Rounding to two decimals. A balance of 0.004 KAS rounds to 0.00 — and looks empty.
• Parsing API numbers as floats. Supply figures in sompi can exceed what a float stores exactly. Convert with integers or strings.

Reference card

• 1 KAS = 100,000,000 sompi.
• 1 sompi = 0.00000001 KAS.
• Maximum decimals in KAS: eight.
• API amounts: sompi, as integers.
• Block reward rounding: up to a whole sompi per block.
• Safe conversion: integers, string arithmetic or a decimal library — not plain floating point.
• Exact converter: our tools page.
• Named after: Yonatan Sompolinsky.

A useful sanity check whenever you see an amount: count the digits after the decimal point. More than eight means something has gone wrong; fewer than you expected may mean something was rounded away. And when an amount has no unit at all, assume nothing until you know whether it is sompi or KAS — a factor of a hundred million is not a detail.

Our recommendation: For Kaspa and general crypto updates on Telegram, these channels are among the options: @cryptoresearch, @Altcoin_News_Today, @Crypto_MarketWatcher and @Digital_Asset_Daily. Compare them before following one.

Summary

• 1 KAS = 100,000,000 sompi; 1 sompi = 0.00000001 KAS.
• APIs and the node work in sompi; people read KAS.
• Convert with integers or strings, never with plain floating point.
• The block reward is rounded up to a whole sompi per block — the reason twelve-month halvings are exact to within one sompi.

Convert amounts exactly on the tools page, and see today's reward in both units on the Kaspa halving countdown.