$6.79 or $7.49 covers it, because swapping mayonnaise for mustard carries no published charge.
A mustard Whopper is a Whopper with mustard in place of mayonnaise, and swapping a condiment carries no published charge. So it costs what a Whopper costs, recorded at $6.79 or $7.49. Calories start from 670, though no company figure covers the modified build. For comparison, adding something real does show up: a Whopper with Cheese was recorded at $7.99, which is 50 cents to $1.20 more.
Whopper price and calories · Whopper with Cheese price, and what cheese adds · Bacon & Cheese Whopper price and calories · Whopper Jr. price and calories · Burger King secret menu — discontinued, not hidden
What you need
8 itemsWhat a change to a Whopper actually costs
| Change | What it costs | Calories |
|---|---|---|
| Mustard in place of mayonnaise | Nothing published — the Whopper price stands at $6.79 or $7.49 | 670 Cal for the standard build |
| Add cheese | Whopper with Cheese $7.99, so 50 cents to $1.20 more | 760 Cal |
| Add bacon and cheese | Bacon & Cheese Whopper $8.79, so $1.30 to $2.00 more | 820 Cal |
| Add a second patty | Double Whopper $8.09 or $9.49 | 920 Cal |
| Go smaller instead | Whopper Jr. $3.99 | 330 Cal |
How it works
Order a Whopper and name the change
Say mustard instead of mayonnaise. Both condiments are on the line already, which is what makes this the least troublesome request on any secret-menu list.
Use the app if the counter is busy
Condiment modifiers are among the few Burger King configures everywhere. Tapping them shows the price staying put, which answers the question this page exists to answer.
Add ketchup only if you want it
A Whopper already carries ketchup alongside the mayonnaise. Swapping one and keeping the other is a different sandwich from swapping both.
Check the receipt if you doubt it
A like-for-like condiment change should leave the line total at the Whopper price. Anything above that is an operator charging for something, and it is worth asking what.
Treat the calorie count as unanswered
Burger King publishes 670 for the standard build and nothing for a modified one. Dropping mayonnaise lowers it by an amount the company has never stated.
If something goes wrong
The receipt showed a charge for the change
- Cause
- Some operators ring extra sauce as an addition rather than a substitution
- Fix
- Ask which line it is. A swap should leave the total at the Whopper price of $6.79 or $7.49, and an addition legitimately does not.
The sandwich arrived with mayonnaise anyway
- Cause
- Modifier notes get missed during a rush, especially at a drive-thru
- Fix
- Check before leaving the window. A remake is quick because nothing unusual is involved, and the request was a standard modifier.
I wanted no ketchup either
- Cause
- A Whopper carries both condiments and removing one leaves the other
- Fix
- Name both changes. Two removals and one addition is still ordinary, though it is worth saying slowly at a speaker.
The calorie count I found does not fit
- Cause
- The published 670 covers the standard build, mayonnaise included
- Fix
- No company figure exists for the modified sandwich. Treat 670 as a ceiling for a version that has had a condiment taken off it.
The total was much higher than $7.49
- Cause
- Extras rather than swaps, or a restaurant pricing above the recorded band
- Fix
- Compare the line against the plain Whopper in the app. Cheese alone took it to $7.99 on the reading recorded here.
The plant-based version behaved differently
- Cause
- An Impossible Whopper is a separate product with its own price
- Fix
- It was recorded at $8.09 or $8.29, and no calorie figure has been published for it. The condiment swap works the same way on either.
What’s fixed, and what actually varies
One of these pages had to be about a build that costs nothing extra. This is that one.
Fixed
- A Whopper carries mayonnaise and ketchup in its standard build
- Swapping one condiment for another is a modifier every till carries
- No published US listing charges for a like-for-like condiment change
- The Whopper itself was recorded at $6.79 or $7.49 for 670 calories
- Adding an ingredient does cost money, unlike swapping one
Varies
- The Whopper, tied at $6.79 or $7.49 across published US listings
- Whether an operator charges for extra sauce on top of a swap
- The Whopper with Cheese figure, which rests on a single reading
- How much the swap changes the calorie count, which nothing published says
- How a franchisee handles requests that go beyond one change
Build a Whopper in the Burger King app with your restaurant selected, then remove the mayonnaise and add mustard while watching the running total. Where the number does not move, the swap is free at that restaurant and the whole question is settled in about ten seconds. Adding rather than swapping is where the total starts climbing.
The cheapest request on any of these lists
Every other build covered in this section costs money. Stacking two sandwiches costs two prices. Adding a patty costs whatever the operator says. This one costs nothing, which is why it is worth a page even though it is the least dramatic thing on the list.
What gets ordered is a Whopper with mustard where the mayonnaise would be. The patty is flame-grilled either way, the lettuce and tomato and pickle are unchanged, and the till treats the request as a substitution rather than an extra. No published US listing carries a charge for that, so the sandwich costs the Whopper price, recorded at $6.79 or $7.49 with the two figures tied.
Setting that against real additions is the useful part. A Whopper with Cheese came back at $7.99, on one reading only, which puts cheese at 50 cents to $1.20 depending on which end of the Whopper tie you start from. A Bacon & Cheese Whopper was recorded at $8.79, so bacon and cheese together run $1.30 to $2.00. A second patty, as a Double Whopper, was $8.09 or $9.49. Going the other way, a Whopper Jr. at $3.99 costs less than any modification could save.
Calories are where the page has to be careful. Burger King publishes 670 for a standard Whopper, 760 with cheese and 820 with bacon and cheese, all from a nutrition document dated November 2022. Nothing published covers a Whopper with the mayonnaise removed, so 670 is a ceiling rather than a count.
One practical note applies at every restaurant. Restaurant Brands International franchises almost the entire US estate, and a franchisee decides how its crew ring up sauce. Where a swap turns into a charge, the sandwich has stopped being a swap somewhere in the till.
Questions people ask
Does a mustard Whopper cost extra?
Nothing published says so. A like-for-like condiment change is a substitution, so the sandwich costs the Whopper price of $6.79 or $7.49.
Is it an official Burger King item?
No. It is a modification of a listed sandwich, which is why it works at every restaurant without anybody needing to recognise a name.
How many calories does it save?
No figure exists. Burger King publishes 670 for the standard build and nothing for one with the mayonnaise taken off, so treat 670 as an upper bound.
What does adding cheese cost?
A Whopper with Cheese was recorded at $7.99 against $6.79 or $7.49 for the plain one, so between 50 cents and $1.20. That rests on a single reading.
And bacon?
A Bacon & Cheese Whopper came to $8.79, which is $1.30 to $2.00 above the plain Whopper. Bacon on its own carries no published price.
Can I do the same on the Impossible Whopper?
Yes, and the swap behaves identically. That sandwich was recorded at $8.09 or $8.29, with no calorie count published for it.
Are these prices from the company?
No US prices are, because Burger King publishes none. These came from published US listings checked on 19 August 2026, and the calorie counts are the company's.