How quickly ???

Hello everyone . I have a mortgage of about 400k which is in month 2 of a 30 year / 7 year arm @5.25. We make about 350k a year and I am wondering what is a reasonable time frame to prepay this mortgage . I love Dave but I am not at the level of rice and beans , beans and rice . We live a moderate lifestyle , take vacations but do not drive luxury cars , watches , etc . I’d like to deleverage myself because we have had a great economic run the last 4 years but I don’t want to assume it will continue .

Thanks,

Pete