diff --git a/lib/wallet.js b/lib/wallet.js
index a1b556d8f..1318acebd 100644
--- a/lib/wallet.js
+++ b/lib/wallet.js
@@ -86,5 +86,68 @@ utils.defineProperty(Wallet, 'getIcapAddress', SigningKey.getIcapAddress);
 
 utils.defineProperty(Wallet, '_Contract', Contract);
 
+var zero = new utils.BN(0);
+var negative1 = new utils.BN(-1);
+var tenPower18 = new utils.BN('1000000000000000000');
+utils.defineProperty(Wallet, 'formatEther', function(wei, options) {
+    if (typeof(wei) === 'number') { wei = new utils.BN(wei); }
+    if (!options) { options = {}; }
+
+    if (!(wei instanceof utils.BN)) { throw new Error('invalid wei'); }
+
+    var negative = wei.lt(zero);
+    if (negative) { wei = wei.mul(negative1); }
+
+    var fraction = wei.mod(tenPower18).toString(10);
+    while (fraction.length < 18) { fraction = '0' + fraction; }
+
+    if (!options.pad) {
+        fraction = fraction.match(/^([0-9]*[1-9]|0)(0*)/)[1];
+    }
+
+    var whole = wei.div(tenPower18).toString(10);
+
+    if (options.commify) {
+        whole = whole.replace(/\B(?=(\d{3})+(?!\d))/g, ",")
+    }
+
+    var value = whole + '.' + fraction;
+
+    if (negative) { value = '-' + value; }
+
+    return value;
+});
+
+utils.defineProperty(Wallet, 'parseEther', function(ether) {
+    if (typeof(ether) !== 'string' || !ether.match(/^-?[0-9.]+$/)) {
+        throw new Error('invalid value');
+    }
+
+    // Is it negative?
+    var negative = (ether.substring(0, 1) === '-');
+    if (negative) { ether = ether.substring(1); }
+
+    if (ether === '.') { throw new Error('invalid value'); }
+
+    // Split it into a whole and fractional part
+    var comps = ether.split('.');
+    if (comps.length > 2) { throw new Error('too many decimal points'); }
+
+    var whole = comps[0], fraction = comps[1];
+    if (!whole) { whole = '0'; }
+    if (!fraction) { fraction = '0'; }
+    if (fraction.length > 18) { throw new Error('too many decimal places'); }
+
+    while (fraction.length < 18) { fraction += '0'; }
+
+    whole = new utils.BN(whole);
+    fraction = new utils.BN(fraction);
+
+    var wei = (whole.mul(tenPower18)).add(fraction);
+
+    if (negative) { wei = wei.mul(negative1); }
+
+    return wei;
+});
 
 module.exports = Wallet;
diff --git a/tests/test-ether-format.js b/tests/test-ether-format.js
new file mode 100644
index 000000000..fd5725dd3
--- /dev/null
+++ b/tests/test-ether-format.js
@@ -0,0 +1,55 @@
+'use strict';
+var Wallet = require('../index.js');
+
+var BN = Wallet.utils.BN;
+
+module.exports = function(test) {
+    function checkFormat(wei, targetEther, options) {
+        var ether = Wallet.formatEther(wei, options);
+        //console.log(wei, targetEther, options, ether);
+        test.equal(ether, targetEther, 'Failed to match formatted ether');
+        ether = ether.replace(/,/g, '');
+        test.ok(Wallet.parseEther(ether).eq(wei), 'Failed to convert back to wei');
+    }
+
+    function checkParse(ether, targetWei) {
+        //console.log(ether, targetWei, Wallet.parseEther(ether));
+        test.ok(targetWei.eq(Wallet.parseEther(ether)), 'Failed to match target wei');
+    }
+
+    checkParse('123.012345678901234567', new BN('123012345678901234567'));
+
+    checkParse('1.0', new BN('1000000000000000000'));
+    checkParse('1', new BN('1000000000000000000'));
+    checkParse('1.00', new BN('1000000000000000000'));
+    checkParse('01.0', new BN('1000000000000000000'));
+
+    checkParse('-1.0', new BN('-1000000000000000000'));
+
+    checkParse('0.1', new BN('100000000000000000'));
+    checkParse('.1', new BN('100000000000000000'));
+    checkParse('0.10', new BN('100000000000000000'));
+    checkParse('.100', new BN('100000000000000000'));
+    checkParse('00.100', new BN('100000000000000000'));
+
+    checkParse('-0.1', new BN('-100000000000000000'));
+
+
+    checkFormat(new BN('10000000000000000'), '0.01');
+    checkFormat(new BN('1000000000000000000'), '1.0');
+    checkFormat(new BN('1230000000000000000'), '1.23');
+    checkFormat(new BN('-1230000000000000000'), '-1.23');
+
+    checkFormat(new BN('1000000000000000000'), '1.000000000000000000', {pad: true});
+    checkFormat(new BN('123000000000000000000'), '123.000000000000000000', {pad: true});
+    checkFormat(new BN('1230000000000000000'), '1.230000000000000000', {pad: true});
+
+    checkFormat(new BN('-1230000000000000000'), '-1.230000000000000000', {pad: true});
+
+    checkFormat(new BN('1234567890000000000000000'), '1,234,567.89', {pad: false, commify: true});
+    checkFormat(new BN('1234567890000000000000000'), '1,234,567.890000000000000000', {pad: true, commify: true});
+    checkFormat(new BN('-1234567890000000000000000'), '-1,234,567.89', {pad: false, commify: true});
+
+
+    test.done();
+}