When bettors and traders compare platforms, one of the first questions they ask is simple:
“How much does each platform actually take?”
That question drives searches around sportsbook vig, Kalshi fees, and Polymarket trading costs. The confusion usually comes from the fact that each platform charges users differently and not always in the same format.
Understanding those differences helps users make better, more informed decisions.
Traditional sportsbooks do not charge a visible transaction fee. Instead, their cost is embedded directly into the odds.
A common example is a −110 line. When a user risks $20 at −110, they win $18.18 instead of a full $20. The difference is the sportsbook’s vig.
That built-in cost typically translates to an effective house edge of roughly 4.5 percent, though it can be higher depending on the market.
The key point is that the cost exists even if it is not explicitly shown.
Kalshi uses sportsbook-style markets but expresses pricing differently. Instead of embedding cost into odds, Kalshi applies an explicit transaction fee to each trade.
Users still choose sides on games, totals, and Yes or No markets. The difference is transparency. The fee is shown directly at the time of the trade.
When translated into familiar betting terms, Kalshi’s total cost often falls into a range similar to traditional sportsbooks. The experience feels different, but the underlying economics are comparable.
Polymarket operates more like a true market, with prices driven by supply and demand.
In liquid markets, total costs tend to be lower than both sportsbooks and Kalshi. This can make small edges more meaningful when prices are tight and volume is high.
Lower fees improve efficiency, but they do not replace the need for strong decision making.
Using approximate, illustrative numbers that vary by market and timing, analysts often summarize total cost to win $100 roughly as follows.
Traditional sportsbooks commonly fall between $5 and $15 depending on odds and market structure.
Kalshi often lands around $7 in comparable scenarios.
Polymarket is frequently closer to $2 in liquid markets.
These figures are not fixed and change based on liquidity, pricing, and timing. They are useful for understanding structure rather than choosing platforms in isolation.
Fees are only one part of the equation.
A slightly lower fee on a poor line is still a poor decision. A slightly higher fee on a strong line can still be a good one.
What matters most is whether the price reflects reality.
Strong decision making starts with understanding expected outcomes and comparing them to what the market is offering. That principle applies across sportsbooks, Kalshi, and Polymarket.
Sportsbooks talk in odds.
Kalshi talks in contracts and trades.
Polymarket talks in markets and prices.
Underneath the labels, the decision is the same.
Is the price aligned with what is likely to happen?
That question is universal across platforms.
Yes, people search for fee comparisons.
Yes, fees differ across platforms.
But long-term results are driven more by price quality than by fee structure alone.
Understanding how each platform works helps users make smarter choices, regardless of whether they are placing bets, trading contracts, or buying market positions.
The platforms may look different.
The terminology may change.
The math stays the same.
