I flushed out my Price-To-Trend-Book-Value thoughts a bit more in this post:
PickTrader writes on Price to Trend Book Value

I described two methods of calculating trend BV, one nominal and one real (inflation-adjusted). The nominal calculation can easily be projected into the future. The real calculation can't since it needs to wait for the monthly inflation numbers.

Here is a chart of trend BV valuations for this year (2023). It makes it easy to quickly check the approximate P/BV.

. . Trend BV . . 1.2x . . . 1.25x . . . 1.3x . . . 1.35x . . . 1.4x
Jan . 218.39 _ 262.07 _ 272.99 _ 283.91 _ 294.83 _ 305.75 . (Trend, inflation-adjusted BV = 233.98)
Feb . 220.23 _ 264.28 _ 275.29 _ 286.30 _ 297.31 _ 308.32 . (Trend, inflation-adjusted BV = 236.85)
Mar . 222.08 _ 266.50 _ 277.60 _ 288.71 _ 299.81 _ 310.92 . (Trend, inflation-adjusted BV will be 238.42 +/- March inflation)
Apr . 223.95 _ 268.74 _ 279.94 _ 291.14 _ 302.34 _ 313.53
May . 225.84 _ 271.01 _ 282.30 _ 293.59 _ 304.88 _ 316.17
Jun . 227.74 _ 273.29 _ 284.67 _ 296.06 _ 307.45 _ 318.83
Jul .. 229.66 _ 275.59 _ 287.07 _ 298.55 _ 310.04 _ 321.52
Aug . 231.59 _ 277.91 _ 289.49 _ 301.07 _ 312.65 _ 324.23
Sep . 233.54 _ 280.25 _ 291.92 _ 303.60 _ 315.28 _ 326.95
Oct . 235.51 _ 282.61 _ 294.38 _ 306.16 _ 317.93 _ 329.71
Nov . 237.49 _ 284.99 _ 296.86 _ 308.73 _ 320.61 _ 332.48
Dec . 239.49 _ 287.38 _ 299.36 _ 311.33 _ 323.31 _ 335.28

Summarizing this thread, the various Price to Book Value ratios are currently (based on Mar 24 BRKB close of 298.92):

1.39x based on the most recent BV of $215.73
1.30x based on peak BV of $230.31
1.37x based on trend BV of $222.08 (Mar 31st)
1.25x based on inflation-adjusted trend BV of $238.42 (Mar 31st)