🧱 钢筋用量计算器Rebar Calculator

使用说明与常见问题How-to & FAQ

「钢筋用量计算器」是什么？What is the Rebar Calculator tool?

按板面尺寸、钢筋间距和保护层计算双向钢筋网需要的根数、总长度、按定尺长度折算的支数和总重量，支持美国 #3–#8 和公制 8–25 mm 钢筋。Work out a two-way rebar grid for a slab: bars each way, total length, stock lengths to buy and total weight from the slab size, spacing and edge cover, for US #3–#8 or metric 8–25 mm bars.

如何使用「钢筋用量计算器」？How do I use the Rebar Calculator tool?

在「钢筋用量计算器」中，填写「单位制」、「板长（英尺/米）」、「板宽（英尺/米）」、「间距（英寸/厘米）」、「边缘保护层（英寸/厘米）」等参数，结果会随输入实时计算并显示在下方。In the Rebar Calculator: Fill in "Units", "Slab length (ft / m)", "Slab width (ft / m)", "Spacing (in / cm)", "Edge cover (in / cm)"; results are recalculated instantly as you type.

钢筋根数怎么算？How is the bar count found?

每个方向的根数 = 可放钢筋的宽度 ÷ 间距（向下取整）+ 1，可放宽度 = 板宽 − 2 × 保护层。总长度含超出定尺时的搭接长度。需购买的定尺支数按“首次适应递减”法排料：先排较长的切段，每段钢筋必须来自同一支定尺，剩余的短料尽量拼给其他切段。Bars each way = usable width ÷ spacing (rounded down) + 1, where usable width = slab width − 2 × cover. Total length includes laps where a run is longer than one stock bar. Stock bars to buy are found by first-fit decreasing packing: longer pieces are placed first, each piece comes from a single stock bar, and offcuts are reused for other pieces where they fit.

钢筋重量依据？Where do the bar weights come from?

美国钢筋按 ASTM A615 标称单位重量：#3 0.376 lb/ft、#4 0.668、#5 1.043、#6 1.502、#8 2.670；公制钢筋按 d²/162 kg/m（如 12 mm 为 0.889 kg/m）。US bars use ASTM A615 nominal weights: #3 0.376 lb/ft, #4 0.668, #5 1.043, #6 1.502, #8 2.670; metric bars use d²/162 kg/m (12 mm = 0.889 kg/m).

搭接长度取多少？How long should laps be?

常见做法为钢筋直径的 40 倍左右（如 #4 约 20 英寸），具体以结构设计和当地规范为准。默认 18 英寸只是示例值，不随规格变化；当钢筋需要搭接且搭接短于 40 × 直径时，结果会提示。规格列表在两种单位制下都可选用美标和公制钢筋。A common rule is about 40 bar diameters (about 20 in for #4), but follow the structural design and local code. The 18 in default is only an example and does not follow the bar size; when bars need laps and the lap is shorter than 40 × diameter, the result points it out. Both US and metric bar sizes can be picked in either unit system.

「钢筋用量计算器」免费吗？需要注册吗？Is the Rebar Calculator free? Do I need an account?

「钢筋用量计算器」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Rebar Calculator is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.