Short answer. The fine ranges from the value of the damage to three times that value, but never less than five thousand pesos. Article 365 of the Revised Penal Code, as amended by RA 10951, sets this formula specifically for reckless imprudence resulting only in property damage, with no injury to any person.
What the law says
When the execution of the act covered by this article shall have only resulted in damage to the property of another, the offender shall be punished by a fine ranging from an amount equal to the value of said damages to three (3) times such value, but which shall in no case be Less than Five thousand pesos (₱5,000)
Revised Penal Code, Article 365 — Imprudence And Negligence. Read the full provision →
What the law says
Reckless imprudence consists in voluntarily, but without malice, doing or failing to do an act from which material damage results by reason of inexcusable lack of precaution on the part of the person performing or failing to perform such act, taking into consideration his employment or occupation, degree of intelligence, physical condition and other circumstances regarding persons, time and place
Revised Penal Code, Article 365 — Imprudence And Negligence. Read the full provision →
What Article 365 sets when the result is property damage only
Article 365 of the Revised Penal Code addresses this exact scenario directly: "When the execution of the act covered by this article shall have only resulted in damage to the property of another, the offender shall be punished by a fine ranging from an amount equal to the value of said damages to three (3) times such value, but which shall in no case be Less than Five thousand pesos (₱5,000)." The fine is pegged to the value of the damage itself, within that range, subject to the stated floor.
Why the ₱5,000 floor needs a caveat
This text is the article as amended by Republic Act No. 10951 in 2017, which revised the property values and fines throughout the Revised Penal Code. Older printings of the Code still carry the pre-2017 figures, so a source that gives you a different floor for this same fine is very likely quoting the article as it stood before that amendment. The current, applicable floor is the five-thousand-peso figure quoted above.
This fine applies whether the imprudence was reckless or simple
The property-damage fine sits after the article describes both reckless imprudence and simple imprudence, and it applies to "the act covered by this article" generally, once the result was limited to property damage — it is not written as a separate, lesser rule reserved only for simple imprudence. Reckless imprudence, as the article defines it, is doing or failing to do an act, voluntarily but without malice, from which material damage results through inexcusable lack of precaution, taking into account the actor's employment, intelligence, physical condition, and the surrounding circumstances.
What this fine doesn't cover
This formula is specific to a result of property damage only. If your reckless driving had also injured someone, the article's earlier paragraphs on imprisonment, graded by the severity of the felony the act would have constituted, would apply instead, and this property-damage fine would not be the governing penalty. The article also directs courts to exercise their sound discretion in imposing these particular penalties, without regard to the usual rules for penalties with three periods.