diff --git a/NEWS.md b/NEWS.md
index 32b2b7ab892db..bc0a7e72ed4b9 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -233,6 +233,8 @@ Library improvements
 
   * The functions `strip`, `lstrip` and `rstrip` now return `SubString` ([#22496]).
 
+  * The functions `strwidth` and `charwidth` have been merged into `textwidth`([#20816]).
+
   * The functions `base` and `digits` digits now accept a negative
     base (like `ndigits` did) ([#21692]).
 
diff --git a/base/deprecated.jl b/base/deprecated.jl
index bd758c9518491..17578096c5fbd 100644
--- a/base/deprecated.jl
+++ b/base/deprecated.jl
@@ -1651,7 +1651,7 @@ end
 end
 
 # PR #23187
-@deprecate cpad(s, n::Integer, p=" ") rpad(lpad(s, div(n+strwidth(s), 2), p), n, p) false
+@deprecate cpad(s, n::Integer, p=" ") rpad(lpad(s, div(n+textwidth(s), 2), p), n, p) false
 
 # PR #22088
 function hex2num(s::AbstractString)
@@ -1877,6 +1877,10 @@ end
     nothing
 end
 
+# issue #20816
+@deprecate strwidth textwidth
+@deprecate charwidth textwidth
+
 # END 0.7 deprecations
 
 # BEGIN 1.0 deprecations
diff --git a/base/dict.jl b/base/dict.jl
index 24aaa18c9dbae..f4b0642759eca 100644
--- a/base/dict.jl
+++ b/base/dict.jl
@@ -1,7 +1,7 @@
 # This file is a part of Julia. License is MIT: https://julialang.org/license
 
 function _truncate_at_width_or_chars(str, width, chars="", truncmark="…")
-    truncwidth = strwidth(truncmark)
+    truncwidth = textwidth(truncmark)
     (width <= 0 || width < truncwidth) && return ""
 
     wid = truncidx = lastidx = 0
@@ -9,7 +9,7 @@ function _truncate_at_width_or_chars(str, width, chars="", truncmark="…")
     while !done(str, idx)
         lastidx = idx
         c, idx = next(str, idx)
-        wid += charwidth(c)
+        wid += textwidth(c)
         wid >= width - truncwidth && truncidx == 0 && (truncidx = lastidx)
         (wid >= width || c in chars) && break
     end
diff --git a/base/exports.jl b/base/exports.jl
index 5d80d9feddfd6..57e0a174cd491 100644
--- a/base/exports.jl
+++ b/base/exports.jl
@@ -730,7 +730,6 @@ export
     bin,
     bits,
     bytes2hex,
-    charwidth,
     chomp,
     chop,
     chr2ind,
@@ -800,8 +799,8 @@ export
     sprint,
     string,
     strip,
-    strwidth,
     summary,
+    textwidth,
     titlecase,
     transcode,
     ucfirst,
diff --git a/base/pkg/entry.jl b/base/pkg/entry.jl
index 1167a7a7e9da4..ad160ae956b9a 100644
--- a/base/pkg/entry.jl
+++ b/base/pkg/entry.jl
@@ -570,7 +570,7 @@ end
 
 function warnbanner(msg...; label="[ WARNING ]", prefix="")
     cols = Base.displaysize(STDERR)[2]
-    str = rpad(lpad(label, div(cols+strwidth(label), 2), "="), cols, "=")
+    str = rpad(lpad(label, div(cols+textwidth(label), 2), "="), cols, "=")
     warn(prefix="", str)
     println(STDERR)
     warn(prefix=prefix, msg...)
diff --git a/base/printf.jl b/base/printf.jl
index dff3d28412df7..2f8347f6f8a95 100644
--- a/base/printf.jl
+++ b/base/printf.jl
@@ -617,11 +617,11 @@ function gen_c(flags::String, width::Int, precision::Int, c::Char)
     blk = Expr(:block, :($x = Char($x)))
     if width > 1 && !('-' in flags)
         p = '0' in flags ? '0' : ' '
-        push!(blk.args, pad(width-1, :($width-charwidth($x)), p))
+        push!(blk.args, pad(width-1, :($width-textwidth($x)), p))
     end
     push!(blk.args, :(write(out, $x)))
     if width > 1 && '-' in flags
-        push!(blk.args, pad(width-1, :($width-charwidth($x)), ' '))
+        push!(blk.args, pad(width-1, :($width-textwidth($x)), ' '))
     end
     :(($x)::Integer), blk
 end
@@ -652,11 +652,11 @@ function gen_s(flags::String, width::Int, precision::Int, c::Char)
             push!(blk.args, :($x = _limit($x, $precision)))
         end
         if !('-' in flags)
-            push!(blk.args, pad(width, :($width-strwidth($x)), ' '))
+            push!(blk.args, pad(width, :($width-textwidth($x)), ' '))
         end
         push!(blk.args, :(write(out, $x)))
         if '-' in flags
-            push!(blk.args, pad(width, :($width-strwidth($x)), ' '))
+            push!(blk.args, pad(width, :($width-textwidth($x)), ' '))
         end
     else
         if precision!=-1
diff --git a/base/repl/LineEdit.jl b/base/repl/LineEdit.jl
index 7c330774fef99..36c8ffb726f19 100644
--- a/base/repl/LineEdit.jl
+++ b/base/repl/LineEdit.jl
@@ -307,8 +307,8 @@ function refresh_multi_line(termbuf::TerminalBuffer, terminal::UnixTerminal, buf
     while moreinput
         l = readline(buf, chomp=false)
         moreinput = endswith(l, "\n")
-        # We need to deal with on-screen characters, so use strwidth to compute occupied columns
-        llength = strwidth(l)
+        # We need to deal with on-screen characters, so use textwidth to compute occupied columns
+        llength = textwidth(l)
         slength = sizeof(l)
         cur_row += 1
         cmove_col(termbuf, lindent + 1)
@@ -319,7 +319,7 @@ function refresh_multi_line(termbuf::TerminalBuffer, terminal::UnixTerminal, buf
             # in this case, we haven't yet written the cursor position
             line_pos -= slength # '\n' gets an extra pos
             if line_pos < 0 || !moreinput
-                num_chars = (line_pos >= 0 ? llength : strwidth(l[1:prevind(l, line_pos + slength + 1)]))
+                num_chars = (line_pos >= 0 ? llength : textwidth(l[1:prevind(l, line_pos + slength + 1)]))
                 curs_row, curs_pos = divrem(lindent + num_chars - 1, cols)
                 curs_row += cur_row
                 curs_pos += 1
@@ -408,7 +408,7 @@ function edit_move_left(buf::IOBuffer)
         #move to the next base UTF8 character to the left
         while true
             c = char_move_left(buf)
-            if charwidth(c) != 0 || c == '\n' || position(buf) == 0
+            if textwidth(c) != 0 || c == '\n' || position(buf) == 0
                 break
             end
         end
@@ -466,7 +466,7 @@ function edit_move_right(buf::IOBuffer)
             pos = position(buf)
             nextc = read(buf,Char)
             seek(buf,pos)
-            (charwidth(nextc) != 0 || nextc == '\n') && break
+            (textwidth(nextc) != 0 || nextc == '\n') && break
         end
         return true
     end
@@ -637,7 +637,7 @@ function edit_backspace(buf::IOBuffer, align::Bool=false, adjust::Bool=false)
     newpos = position(buf)
     if align && c == ' ' # maybe delete multiple spaces
         beg = beginofline(buf, newpos)
-        align = strwidth(String(buf.data[1+beg:newpos])) % 4
+        align = textwidth(String(buf.data[1+beg:newpos])) % 4
         nonspace = findprev(_notspace, buf.data, newpos)
         if newpos - align >= nonspace
             newpos -= align
@@ -950,7 +950,7 @@ end
 function write_prompt(terminal, s::Union{AbstractString,Function})
     promptstr = prompt_string(s)
     write(terminal, promptstr)
-    strwidth(promptstr)
+    textwidth(promptstr)
 end
 
 ### Keymap Support
@@ -1697,7 +1697,7 @@ function edit_insert_tab(buf::IOBuffer, jump_spaces=false, delete_trailing=jump_
         end
     end
     # align to multiples of 4:
-    align = 4 - strwidth(String(buf.data[1+beginofline(buf, i):i])) % 4
+    align = 4 - textwidth(String(buf.data[1+beginofline(buf, i):i])) % 4
     edit_insert(buf, ' '^align)
     return true
 end
diff --git a/base/show.jl b/base/show.jl
index 3f6aad653eab7..1ad119d814e83 100644
--- a/base/show.jl
+++ b/base/show.jl
@@ -1682,7 +1682,7 @@ function print_matrix(io::IO, X::AbstractVecOrMat,
     screenwidth -= length(pre) + length(post)
     presp = repeat(" ", length(pre))  # indent each row to match pre string
     postsp = ""
-    @assert strwidth(hdots) == strwidth(ddots)
+    @assert textwidth(hdots) == textwidth(ddots)
     sepsize = length(sep)
     rowsA, colsA = indices(X,1), indices(X,2)
     m, n = length(rowsA), length(colsA)
diff --git a/base/strings/basic.jl b/base/strings/basic.jl
index 71edd09db674a..29b639e5b42b3 100644
--- a/base/strings/basic.jl
+++ b/base/strings/basic.jl
@@ -389,21 +389,6 @@ next(e::EachStringIndex, state) = (state, nextind(e.s, state))
 done(e::EachStringIndex, state) = done(e.s, state)
 eltype(::Type{EachStringIndex}) = Int
 
-## character column width function ##
-
-"""
-    strwidth(s::AbstractString)
-
-Give the number of columns needed to print a string.
-
-# Examples
-```jldoctest
-julia> strwidth("March")
-5
-```
-"""
-strwidth(s::AbstractString) = (w=0; for c in s; w += charwidth(c); end; w)
-
 """
     isascii(c::Union{Char,AbstractString}) -> Bool
 
diff --git a/base/strings/utf8proc.jl b/base/strings/utf8proc.jl
index 3c82902a1c01b..70e406097303a 100644
--- a/base/strings/utf8proc.jl
+++ b/base/strings/utf8proc.jl
@@ -8,7 +8,7 @@ import Base: show, ==, hash, string, Symbol, isless, length, eltype, start, next
 export isgraphemebreak, category_code, category_abbrev, category_string
 
 # also exported by Base:
-export normalize_string, graphemes, is_assigned_char, charwidth, isvalid,
+export normalize_string, graphemes, is_assigned_char, textwidth, isvalid,
    islower, isupper, isalpha, isdigit, isnumber, isalnum,
    iscntrl, ispunct, isspace, isprint, isgraph
 
@@ -208,21 +208,35 @@ end
 
 ############################################################################
 
+## character column width function ##
 """
-    charwidth(c)
+    textwidth(c)
 
-Gives the number of columns needed to print a character.
+Give the number of columns needed to print a character.
 
 # Examples
 ```jldoctest
-julia> charwidth('α')
+julia> textwidth('α')
 1
 
-julia> charwidth('❤')
+julia> textwidth('❤')
 2
 ```
 """
-charwidth(c::Char) = Int(ccall(:utf8proc_charwidth, Cint, (UInt32,), c))
+textwidth(c::Char) = Int(ccall(:utf8proc_charwidth, Cint, (UInt32,), c))
+
+"""
+    textwidth(s::AbstractString)
+
+Give the number of columns needed to print a string.
+
+# Examples
+```jldoctest
+julia> textwidth("March")
+5
+```
+"""
+textwidth(s::AbstractString) = mapreduce(textwidth, +, 0, s)
 
 lowercase(c::Char) = isascii(c) ? ('A' <= c <= 'Z' ? c + 0x20 : c) : Char(ccall(:utf8proc_tolower, UInt32, (UInt32,), c))
 uppercase(c::Char) = isascii(c) ? ('a' <= c <= 'z' ? c - 0x20 : c) : Char(ccall(:utf8proc_toupper, UInt32, (UInt32,), c))
diff --git a/base/strings/util.jl b/base/strings/util.jl
index 665fae4c6398d..2d3e646109055 100644
--- a/base/strings/util.jl
+++ b/base/strings/util.jl
@@ -204,9 +204,9 @@ strip(s::AbstractString, chars::Chars) = lstrip(rstrip(s, chars), chars)
 ## string padding functions ##
 
 function lpad(s::AbstractString, n::Integer, p::AbstractString=" ")
-    m = n - strwidth(s)
+    m = n - textwidth(s)
     (m <= 0) && (return s)
-    l = strwidth(p)
+    l = textwidth(p)
     if l==1
         return string(p^m, s)
     end
@@ -217,9 +217,9 @@ function lpad(s::AbstractString, n::Integer, p::AbstractString=" ")
 end
 
 function rpad(s::AbstractString, n::Integer, p::AbstractString=" ")
-    m = n - strwidth(s)
+    m = n - textwidth(s)
     (m <= 0) && (return s)
-    l = strwidth(p)
+    l = textwidth(p)
     if l==1
         return string(s, p^m)
     end
diff --git a/doc/src/stdlib/strings.md b/doc/src/stdlib/strings.md
index 9be348f2ec9f8..003b9b1b92b6d 100644
--- a/doc/src/stdlib/strings.md
+++ b/doc/src/stdlib/strings.md
@@ -59,8 +59,7 @@ Base.chr2ind
 Base.nextind
 Base.prevind
 Base.Random.randstring
-Base.UTF8proc.charwidth
-Base.strwidth
+Base.UTF8proc.textwidth
 Base.UTF8proc.isalnum
 Base.UTF8proc.isalpha
 Base.isascii
diff --git a/test/dict.jl b/test/dict.jl
index 45245f457185b..8c0f22e383592 100644
--- a/test/dict.jl
+++ b/test/dict.jl
@@ -274,7 +274,7 @@ end
             Base.show(io, MIME("text/plain"), d)
             out = split(String(take!(s)),'\n')
             for line in out[2:end]
-                @test strwidth(line) <= cols
+                @test textwidth(line) <= cols
             end
             @test length(out) <= rows
 
@@ -284,7 +284,7 @@ end
                 Base.show(io, MIME("text/plain"), f(d))
                 out = split(String(take!(s)),'\n')
                 for line in out[2:end]
-                    @test strwidth(line) <= cols
+                    @test textwidth(line) <= cols
                 end
                 @test length(out) <= rows
             end
diff --git a/test/unicode/utf8proc.jl b/test/unicode/utf8proc.jl
index 2c70ed21291f8..ef05772064913 100644
--- a/test/unicode/utf8proc.jl
+++ b/test/unicode/utf8proc.jl
@@ -266,16 +266,17 @@ end
 end
 
 @testset "#3721, #6939 up-to-date character widths" begin
-    @test charwidth('\U1f355') == 2
-    @test strwidth("\U1f355") == 2
-    @test strwidth(GenericString("\U1f355")) == 2
-    @test strwidth("\U1f355\u0302") == 2
-    @test strwidth(GenericString("\U1f355\u0302")) == 2
+    @test textwidth("") == 0
+    @test textwidth('\U1f355') == 2
+    @test textwidth("\U1f355") == 2
+    @test textwidth(GenericString("\U1f355")) == 2
+    @test textwidth("\U1f355\u0302") == 2
+    @test textwidth(GenericString("\U1f355\u0302")) == 2
 end
 
 @testset "#10958 handling of embedded NUL chars" begin
     @test length("\0w") == length("\0α") == 2
-    @test strwidth("\0w") == strwidth("\0α") == 1
+    @test textwidth("\0w") == textwidth("\0α") == 1
     @test normalize_string("\0W", casefold=true) == "\0w"
 end