An F1 car must meet its minimum mass throughout the competition.

The governing body and version used here

This page covers the 2026 FIA Formula One World Championship, a global championship governed by the Fédération Internationale de l'Automobile. It applies FIA Section A, General Regulatory Provisions, Issue 03 dated 25 June 2026; Section B, Sporting Regulations, Issue 08 dated 5 August 2026; and Section C, Technical Regulations, Issue 20 dated 5 August 2026.

Section A says the 2026 regulations came into force on 1 January 2026. The later Section B and C issues incorporate amendments approved by the World Motor Sport Council on 3 August 2026. This is not a guide to Formula 2, Formula 3, historic Formula One or a national single-seater series.

Passing one check does not certify the car for the weekend

Technical Article C1.3 requires the car to comply in its entirety at all times during a Competition. Article C1.5 puts the burden on the competitor to satisfy the FIA and the stewards that it complies. Under Sporting Article B1.2.3, the Technical Delegate may arrange compliance checks at any time until the Competition ends.

Why the regulations do not print one final kilogram total

Under Article C4.7, the tyre supplier measures new production dry-weather tyres before the championship. The Nominal Tyre Mass is based on the mean of a 50-tyre sample for each axle and is published separately. It may be adjusted if the tyre specification changes during the championship.

The safe way to quote the rule is therefore the Article C4.1 formula. A media number that combines the base and a tyre value can become stale even while the base in C4.1 remains unchanged.

If a car presented for checking is not already on dry-weather tyres, Article C4.1 says its mass is determined using a set of dry-weather tyres selected by the FIA Technical Delegate. A wet-tyre set is not allowed to distort the comparison.

A lighter driver does not create free movable ballast

Article C4.5 requires the FIA-established reference mass of the driver plus Driver Ballast to be at least 82kg throughout the Competition. The Technical Delegate establishes the driver's reference mass at the first Competition and may amend it during the season.

• Driver Ballast has a prescribed area: it must lie between the front and rear limits of the cockpit-entry template.
• It must be secure and traceable: Article C4.3.2 requires attachment to the survival cell, an FIA seal and clear identification.
• It cannot do another job: it must have no additional function and must meet the specified density requirement.
• Other ballast is also fixed: general ballast must require tools for removal and remain immobile relative to the complete sprung mass; the Technical Delegate must be able to seal it if necessary.

A declared heat hazard changes both equipment and mass

Under Sporting Article B1.5.10, a Heat Hazard may be declared for the Sprint, Race or both if the official forecast predicts a Heat Index above 31.0°C, or at the Race Director's sole discretion. The declaration is made 24 hours before the scheduled start of the Competition.

• Declared Sprint or Race: Technical Article C4.6 adds 5kg to the minimum for that total-time classified session. The relevant cooling-equipment and clothing mass must total at least 5kg.
• Other sessions at that Competition: if a Heat Hazard has been declared for any session, a 2kg increase applies to each session for which it has not been declared, and the driver-cooling system must weigh at least 2kg.
• Driver opts out of cooling clothing: the other cooling-system components and cooling medium remain required, and Sporting Article B1.5.10 requires 0.5kg of cockpit ballast to compensate for the omitted personal-equipment items.

The heat increase is part of the legal minimum; it is not spare ballast the team may remove. For the separate qualifying axle-distribution test in C4.2, however, the heat increase is not counted.

A team cannot replenish lost mass at will

Technical Article C4.4 says that, apart from compressed gases, no substance may be added during the Sprint or Race. If a part has to be replaced during either session, the replacement must not be heavier than the original.

That is distinct from normal pit work permitted by the sporting rules. A team cannot add fluid, a heavier component or another substance merely to recover a mass margin before the finish or a later check.

Who goes to the scales in lap-time sessions

Free practice, Sprint Qualifying and Qualifying are “Lap Time Classified Sessions” under the 2026 terminology. Sporting Article B3.2.1 controls weighing after any such session and during Sprint Qualifying or Qualifying.

1. Selected driver reports directly: when signalled, the driver must go to the FIA garage and stop the engine.
2. No intervening work: failing to stop and return, or having work done before return to the FIA garage, is referred to the stewards.
3. Each driver is weighed: the Technical Delegate weighs every driver at the end of the last qualifying period in which that driver participated.
4. Q3 and SQ3 cars are automatic: every car that took part in Q3 or SQ3 is weighed at the end of that session.
5. A driver who left a stopped car still reports: after returning to the pit lane, that driver must go immediately to the FIA garage so the driver's mass can be established.

Any classified finisher may be weighed

The Sprint and Race are “Total Time Classified Sessions.” After either, Article B3.2.2 allows any classified car to be weighed. If the driver wants to leave first, the driver must present themself to the Technical Delegate and request a separate weighing so that mass can be added to the car's measurement.

Selection is not proof that an unselected car has passed the same check, and Article B3.2.2 does not require every classified car to be weighed. Article B3.1.8 says the stewards publish scrutineering findings whenever cars are checked, but specific figures are withheld unless a car is in breach.

Once selected, the measured condition is protected

Article B3.2.4 forbids adding, placing on or removing any substance after the car has been selected for weighing, after it has finished a Sprint or Race, or during the weighing procedure. Only a scrutineer acting officially may do so.

A breach of the weighing procedure is separate from being underweight. Under B3.2.5 the stewards may impose grid-position drops or disqualify the driver from the Sprint or Race. This is why following the weighbridge instruction matters even if the team believes the car is comfortably above the minimum.

Accidental component loss is narrow, not automatic

Article B3.2.3 says a car below C4.1 may be disqualified, except where the deficiency results from the accidental loss of a car component. The decisive questions are therefore whether a component was lost, whether the loss was accidental and whether it caused the measured shortfall.

• Ordinary consumption, tyre wear, plank wear or a small design margin is not described in B3.2.3 as accidental component loss.
• The rule does not say that visible damage automatically restores the missing mass or excuses an unrelated dimension, wear, fuel or construction breach.
• The Technical Delegate establishes and reports the technical facts; the stewards decide whether to apply the sporting consequence.

Claims the 2026 rules do not support

• “The minimum is one fixed number.” The base changes for qualifying, the nominal tyre value is separate, and a heat increase may apply.
• “Fuel can save an underweight car.” Fuel is excluded from the defined Car Mass.
• “Only the top three are weighed.” Q3 and SQ3 cars are all weighed; any classified Sprint or Race car may be selected.
• “Damage always excuses the shortfall.” The text requires accidental loss of a component to have caused the deficiency.
• “A technical breach proves cheating.” Compliance and intent are different questions. Section A makes the team responsible for non-compliance, while the applicable article and stewards' decision control the consequence.
• “Scrutineering ends at the scales.” Dismantling, parts, samples, seals, CAD, software, data and physical measurement can all form part of the process.

Continue with Formula 1 procedures

• Parc fermé and car setup rules explain which changes remain permitted while cars are under controlled conditions.
• Black flags and disqualifications explain how exclusion from a session or classification differs from an instruction to stop.
• F1 penalties and penalty points cover the wider sanction framework.
• Formula 1 rules in five minutes gives the championship overview.