RSU Calculator: Grant Value, Vesting & Tax Owed 2026

Your RSU grant is not worth what the grant letter says

The grant letter says 1,000 shares at $50 — $50,000 on paper. What you keep is less, and the reason is the tax rule that makes RSUs different from every other kind of pay: RSUs are taxed as ordinary income AT VEST, on the value that day. You do not own the shares until they vest, and on the day they vest the value counts as salary — taxed at your marginal rate, in the year it vests. The grant value is not what you keep, and the tax withholding at vest — often 22% federal supplemental — is only a down payment on the tax you may owe at your marginal rate. If your marginal rate is 37%, the 22% withheld at vest leaves 15% still to pay at tax time. The formula is simple: total grant value = shares × share price; shares per vest = shares / vesting years; value per vest = shares per vest × share price; tax per vest = value per vest × tax rate; net per vest = value per vest × (1 − tax rate); total net = shares × share price × (1 − tax rate); monthly equivalent = net per vest / 12. On the defaults — 1,000 shares, $50 a share, 4 years, 22% tax — the grant is $50,000.00, each vest is 250 shares worth $12,500.00, the tax on each vest is $2,750.00, and you keep $9,750.00 per vest — $39,000.00 in total, or $812.50 a month. At 5% growth a year, the price at full vest is $50 × 1.05^4 = $60.78, the projected grant is $60,775.31, and the projected net is $47,404.74.

At the defaults — shares 1,000, share price $50, vesting 4 years, tax 22%, growth 5% — the grant value is $50,000.00, the shares per vest are 250, the value per vest is $12,500.00, the tax per vest is $2,750.00, the net per vest is $9,750.00, the total net is $39,000.00, the monthly equivalent is $812.50, the projected price at full vest is $60.78, the projected grant is $60,775.31, and the projected net is $47,404.74. Check the identities: grant = shares × price; vest = shares / years × price; net = vest × (1 − tax); total net = shares × price × (1 − tax); monthly = net / 12; projected price = price × (1 + growth)^years; projected net = shares × projected price × (1 − tax). The projected figures assume the price grows at the same rate every year and the tax rate stays the same — neither is guaranteed. Rounding convention: totals are computed from unrounded values, so rounded parts may differ by a cent from their rounded sum.

The worked example, line by line

Setup: 1,000 shares, share price $50, vesting 4 years, tax rate 22%, growth 5%.

Line 1 — the grant value. 1,000 × $50 = $50,000.00.

Line 2 — the shares per vest. 1,000 / 4 = 250 shares.

Line 3 — the value per vest. 250 × $50 = $12,500.00.

Line 4 — the tax per vest. $12,500.00 × 22% = $2,750.00.

Line 5 — the net per vest. $12,500.00 × (1 − 0.22) = $9,750.00.

Line 6 — the total net. 1,000 × $50 × 0.78 = $39,000.00.

Line 7 — the monthly equivalent. $9,750.00 / 12 = $812.50.

Line 8 — the projected price at full vest. $50 × 1.05^4 = $60.78.

Line 9 — the projected grant. 1,000 × $60.78 = $60,775.31.

Line 10 — the projected net. $60,775.31 × 0.78 = $47,404.74.

Reverse: the shares for a $100,000 total net are 2,564 (exact 2564.1026); at 2,564 shares the total net is $99,996.00 ($4.00 under), at 2,565 shares it is $100,035.00 ($35.00 over) — 2,564 is the nearest. The share price for a $50,000 total net is $64.10 (exact 64.1026); at $64.10 the total net is $49,998.00 ($2.00 under), at $64.11 it is $50,005.80 ($5.80 over) — $64.10 is the nearest. The tax rate for a $45,000 total net is 10% (exact); at 10% the total net is $45,000.00 exactly. The vesting years for a $5,000 net per vest are 7.8 years (exact); at 7.8 years the net per vest is $5,000.00 exactly. The growth rate for a $75,000 projected grant is 10.67% (exact 10.6682%); at 10.67% the projected grant is $75,004.90 ($4.90 over), at 10.66% it is $74,977.80 ($22.20 under) — 10.67% is the nearest.

Every branch, checked

500 shares: grant $25,000.00, vest $6,250.00, net $4,875.00, total net $19,500.00, projected net $23,702.37. Half the shares, half the money — the grant scales exactly with the share count.

2,000 shares: grant $100,000.00, vest $25,000.00, net $19,500.00, total net $78,000.00, projected net $94,809.49. A six-figure grant still keeps only 78 cents on the dollar after 22% tax.

Share price $25: grant $25,000.00, vest $6,250.00, net $4,875.00, total net $19,500.00, projected net $23,702.37. Half the price, half the grant — the same numbers as 500 shares at $50, because shares × price is what matters.

Share price $100: grant $100,000.00, vest $25,000.00, net $19,500.00, total net $78,000.00, projected net $94,809.49. The same numbers as 2,000 shares at $50 — again, shares × price is the whole story.

3 vesting years: grant $50,000.00, vest $16,666.67, net $13,000.00, total net $39,000.00, projected net $45,147.38. Fewer years means bigger vests — 333.33 shares a year instead of 250 — but the same total net, because the tax rate is the same.

5 vesting years: grant $50,000.00, vest $10,000.00, net $7,800.00, total net $39,000.00, projected net $49,774.98. Smaller vests, same total net — but a longer wait means more growth, so the projected net is higher.

Tax rate 12%: grant $50,000.00, vest $12,500.00, net $11,000.00, total net $44,000.00, projected net $53,482.28. Ten points less tax keeps $5,000 more of the grant.

Tax rate 37%: grant $50,000.00, vest $12,500.00, net $7,875.00, total net $31,500.00, projected net $38,288.45. At the top marginal rate you keep 63 cents on the dollar — and the 22% withheld at vest leaves 15% still to pay.

Growth 0%: grant $50,000.00, vest $12,500.00, net $9,750.00, total net $39,000.00, projected net $39,000.00. No growth means the projected net is the same as today’s net.

Growth 10%: grant $50,000.00, vest $12,500.00, net $9,750.00, total net $39,000.00, projected net $57,099.90. Doubling the growth rate adds more than $9,600 to the projected net — growth compounds over the vesting years.

Reverse — the other way round: the shares for a $100,000 total net are 2,564 (exact 2564.1026); the share price for a $50,000 total net is $64.10 (exact 64.1026); the tax rate for a $45,000 total net is 10% (exact); the vesting years for a $5,000 net per vest are 7.8 years (exact); the growth rate for a $75,000 projected grant is 10.67% (exact 10.6682%).

What the defaults assume

The model assumes straight-line annual vesting — the same number of shares each year — and it assumes the tax is worked out on the value at each vest at one flat marginal rate. It assumes the share price grows at the same rate every year until full vesting, and it assumes the tax rate stays the same. It leaves out state tax, Social Security and Medicare on the vested value, the cliff — many grants vest nothing in the first year — and what happens if you leave before the grant vests: unvested shares are forfeited. With 0 shares, everything is $0.00. With a 0% tax rate, the total net is $50,000.00 — the net is the grant — and the projected net is $60,775.31. With a 50% tax rate, the total net is $25,000.00 and the net per vest is $6,250.00. With −10% growth a year, the projected price is $32.81 and the projected net is $25,587.90 — the grant shrinks, and so does what you keep. Rounding convention: totals are computed from unrounded values, so rounded parts may differ by a cent from their rounded sum; the reverses are nearest-value solutions, and the exact unrounded figures (2564.1026, 64.1026, 10%, 7.8 years, 10.6682%) are stated wherever the rounded figures appear.

Output · formula · meaning

Who uses this

• The new hire with a 1,000-share grant: they learn the $50,000 grant is $39,000.00 after 22% tax — $9,750.00 a vest, $812.50 a month — so they know what the offer is really worth, and they check the 37% branch ($31,500.00) before counting on the full amount.
• The employee whose shares just vested: they learn each vest is $12,500.00 of income and $2,750.00 of tax — so they know the 22% withheld at vest is only a down payment if their marginal rate is higher, and they check the $64.10 reverse before planning what the next vest is worth.
• The employee deciding whether to hold or sell: they learn at 5% growth the grant is worth $47,404.74 after tax at full vest — so they know what holding is worth, and they check the −10% growth edge ($25,587.90) before assuming the price only goes up.
• The job-seeker comparing two offers: they learn 2,564 shares are needed for a $100,000 total net at $50 and 22% tax — so they know how to compare a bigger grant against a higher salary, and they check the 2,000-share branch ($78,000.00 total net) before choosing the offer with the bigger headline number.

Accuracy & limitations

The math is exact for the numbers you enter: grant = shares × price; vest = shares / years × price; tax = vest × tax rate; net = vest × (1 − tax); total net = shares × price × (1 − tax); monthly = net / 12; projected price = price × (1 + growth)^years; projected net = shares × projected price × (1 − tax). What the model cannot do is know your real tax rate: check it, because the tax is worked out at your marginal rate and the 22% withheld at vest is only a down payment — and check the vesting schedule, because many grants have a one-year cliff and forfeit unvested shares if you leave. It assumes straight-line annual vesting, one flat tax rate, and the same growth every year. It leaves out state tax, Social Security and Medicare on the vested value, and the price on the actual vest dates. It is a value calculator, not tax advice: for what lands in your bank account, see the take-home pay calculator; for whether the salary or the grant wins, see the salary vs freelance calculator.