Bid increments are the least discussed setting on any auction platform and one of the most consequential. Too large, and you shut out bidders who’d have gone a little higher. Too small, and lots take forever while bidders lose interest. Both cost money, and neither shows up in any report.
TL;DR: how to set bid increments
- Use a table that scales with price, not one fixed number
- Aim for each step to be roughly 2% to 5% of the current bid
- With proxy bidding, the winner usually pays the underbidder’s max plus one increment, so increment size directly sets your hammer
- Pair increments with a 2 to 5 minute soft close, allow per-lot overrides, and let bidders enter custom amounts
- Check your closing prices once a year and adjust the bands that stall
Our auction software ships with configurable increment tables, proxy bidding and soft close, on a one-time license.
What an increment actually is
It’s the minimum amount by which a new bid must beat the current high bid. On any serious platform it isn’t one number but a table that scales with price. Here’s a sensible starting shape:
| Current bid | Increment | Step as % of bid |
|---|---|---|
| $0 to $100 | $5 | 5% or more |
| $100 to $500 | $10 | 2% to 10% |
| $500 to $1,000 | $25 | 2.5% to 5% |
| $1,000 to $5,000 | $50 | 1% to 5% |
| $5,000 to $25,000 | $250 | 1% to 5% |
| $25,000+ | $1,000 | 4% or less |
Treat that as an illustration rather than a prescription, because the right table depends on your category. The principle holds everywhere, though: keep each step at roughly 2% to 5% of the current price. Below that, bidding drags. Above it, you start excluding people.
How increments interact with proxy bidding
This is where most confusion comes from. With proxy bidding, a bidder sets a maximum and the system bids for them one increment at a time.
The result is that the winning price is usually the underbidder’s maximum plus one increment, not the winner’s maximum. So increment size directly sets the gap between what the market would pay and what you collect.
Say the underbidder maxed out at $1,220. With a $50 increment the winner pays $1,270, and with a $25 increment they pay $1,245. Across a 400-lot catalogue that’s real money, and it can run either way depending on where the maximums fall.
What goes wrong at each end
Increments that are too large stop bidders who are at their limit, because they can’t take one more small step. They make low-value lots unbiddable (a $10 increment on a $15 item is absurd), and the jumps feel arbitrary, so people disengage.
Too small is a different kind of damage. Lots take ages to reach real money, which kills the pace of a live sale. Bidding wars turn tedious instead of exciting. And proxy bidding generates huge numbers of automated micro-bids, which is a server-load problem as well as a user-experience one.
Bid increments by category
| Category | Typical increments | Why |
|---|---|---|
| General estate and household | Start at $1 to $5, scale steeply | Much of the catalogue is low value |
| Vehicles | $100 to $250 in the retail range | Small steps on a $20,000 car waste everyone’s time |
| Heavy equipment | $250 to $1,000 | Bidders think in thousands |
| Fine art and antiques | Saleroom steps, a 10-20-50 progression per decade of value | Convention bidders expect |
| Collectibles and cards | Finer than most | Grade differences are precise, and bidders bid to them |
| Charity auctions | 5% to 10% of the starting bid, in round numbers | Guests aren’t calculating |
For the full car and equipment setups, see car auction software and farm equipment auction software. For charity events, see how to run a silent auction.
Two settings worth having
Per-lot overrides come first. Your standard table will be wrong for some lots, and a high-value item in a low-value sale needs its own increments. Make it easy for whoever does the cataloguing.
Custom bid amounts come second. Letting bidders enter any amount above the minimum, not just the next step, captures the bidder who wants to jump. Jump bidding is a real strategy (a bidder signalling seriousness to scare off competition), and platforms that block it lose those bids.
Increments and soft close together
These two interact, so tune them together. Very small increments with a long soft-close extension produce auctions that run for hours while bidders creep upward. Large increments with no soft close produce sniping.
What generally works: increments at roughly 2% to 5% of the current price, and a soft-close extension of two to five minutes on any bid in the final window. That’s enough to stop sniping and short enough that lots actually finish.
Testing your table
Pull your last few sales and look at where lots closed. If a good share closed exactly one increment above a round number, your increments are probably fine. If lots stall just below where you’d expect, or the same bidders keep stopping at the same point, your steps are too coarse in that band.
It’s worth an hour of analysis, once. Most operators set increments when they configure the platform and never look again.
Setting increments in our software
Our auctioneer software lets you set your own increment rules, together with proxy bidding, reserve prices, soft close and popcorn bidding (the full list is on the features page). Because it runs on your own server, the rules are yours, not a marketplace’s defaults. It’s a one-time license, $899 to $2,999. The Professional and Enterprise tiers include custom development hours if your category needs unusual increment logic.
See increments and soft close in action
Place a few bids on the live demo, compare license options, or ask us about your category.
Related reading: absolute vs. reserve auctions, sealed bid vs. open outcry, what a buyer’s premium is, and the anatomy of a high-converting auction product page.
Frequently asked questions
What is a bid increment?
The minimum amount a new bid must exceed the current high bid by. Most platforms use a table where the increment grows as the price rises.
What is a good bid increment percentage?
Roughly 2% to 5% of the current price works across most categories. Tune it from your own closing data rather than treating it as a rule.
How do bid increments work with proxy bidding?
The system raises the leading bidder’s bid one increment at a time, up to their maximum. The winner usually pays the second-highest maximum plus one increment.
Should bidders be able to bid any amount?
Generally yes, as long as it’s above the minimum. Jump bidding is a legitimate strategy, and blocking it loses bids from your most motivated buyers.
Can increments differ per lot?
They should. A standard table plus per-lot overrides is the right structure. Talk to our team if your current platform can’t do this.
What bid increment should I use for a charity auction?
Around 5% to 10% of the starting bid, in round numbers like $5, $10, $25 or $50. Guests decide quickly, and odd amounts slow them down.
